TLS vulnerabilities

Issue summary: A TLS 1.3 connection using certificate compression can be forced to allocate a large buffer before decompression without checking against the configured certificate size limit. Impact summary: An attacker can cause per-connection memory allocations of up to approximately 22 MiB and extra CPU work, potentially leading to service degradation or resource exhaustion (Denial of Service). In affected configurations, the peer-supplied uncompressed certificate length from a CompressedCertificate message is used to grow a heap buffer prior to decompression. This length is not bounded by the max_cert_list setting, which otherwise constrains certificate message sizes. An attacker can exploit this to cause large per-connection allocations followed by handshake failure. No memory corruption or information disclosure occurs. This issue only affects builds where TLS 1.3 certificate compression is compiled in (i.e., not OPENSSL_NO_COMP_ALG) and at least one compression algorithm (brotli, zlib, or zstd) is available, and where the compression extension is negotiated. Both clients receiving a server CompressedCertificate and servers in mutual TLS scenarios receiving a client CompressedCertificate are affected. Servers that do not request client certificates are not vulnerable to client-initiated attacks. Users can mitigate this issue by setting SSL_OP_NO_RX_CERTIFICATE_COMPRESSION to disable receiving compressed certificates. The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the TLS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Issue summary: The 'openssl dgst' command-line tool silently truncates input data to 16MB when using one-shot signing algorithms and reports success instead of an error. Impact summary: A user signing or verifying files larger than 16MB with one-shot algorithms (such as Ed25519, Ed448, or ML-DSA) may believe the entire file is authenticated while trailing data beyond 16MB remains unauthenticated. When the 'openssl dgst' command is used with algorithms that only support one-shot signing (Ed25519, Ed448, ML-DSA-44, ML-DSA-65, ML-DSA-87), the input is buffered with a 16MB limit. If the input exceeds this limit, the tool silently truncates to the first 16MB and continues without signaling an error, contrary to what the documentation states. This creates an integrity gap where trailing bytes can be modified without detection if both signing and verification are performed using the same affected codepath. The issue affects only the command-line tool behavior. Verifiers that process the full message using library APIs will reject the signature, so the risk primarily affects workflows that both sign and verify with the affected 'openssl dgst' command. Streaming digest algorithms for 'openssl dgst' and library users are unaffected. The FIPS modules in 3.5 and 3.6 are not affected by this issue, as the command-line tools are outside the OpenSSL FIPS module boundary. OpenSSL 3.5 and 3.6 are vulnerable to this issue. OpenSSL 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL dereference occurs. Impact summary: A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service. Some applications call SSL_CIPHER_find() from the client_hello_cb callback on the cipher ID received from the peer. If this is done with an SSL object implementing the QUIC protocol, NULL pointer dereference will happen if the examined cipher ID is unknown or unsupported. As it is not very common to call this function in applications using the QUIC protocol and the worst outcome is Denial of Service, the issue was assessed as Low severity. The vulnerable code was introduced in the 3.2 version with the addition of the QUIC protocol support. The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the QUIC implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Issue summary: PBMAC1 parameters in PKCS#12 files are missing validation which can trigger a stack-based buffer overflow, invalid pointer or NULL pointer dereference during MAC verification. Impact summary: The stack buffer overflow or NULL pointer dereference may cause a crash leading to Denial of Service for an application that parses untrusted PKCS#12 files. The buffer overflow may also potentially enable code execution depending on platform mitigations. When verifying a PKCS#12 file that uses PBMAC1 for the MAC, the PBKDF2 salt and keylength parameters from the file are used without validation. If the value of keylength exceeds the size of the fixed stack buffer used for the derived key (64 bytes), the key derivation will overflow the buffer. The overflow length is attacker-controlled. Also, if the salt parameter is not an OCTET STRING type this can lead to invalid or NULL pointer dereference. Exploiting this issue requires a user or application to process a maliciously crafted PKCS#12 file. It is uncommon to accept untrusted PKCS#12 files in applications as they are usually used to store private keys which are trusted by definition. For this reason the issue was assessed as Moderate severity. The FIPS modules in 3.6, 3.5 and 3.4 are not affected by this issue, as PKCS#12 processing is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5 and 3.4 are vulnerable to this issue. OpenSSL 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue as they do not support PBMAC1 in PKCS#12.

Issue summary: Parsing CMS AuthEnvelopedData or EnvelopedData message with maliciously crafted AEAD parameters can trigger a stack buffer overflow. Impact summary: A stack buffer overflow may lead to a crash, causing Denial of Service, or potentially remote code execution. When parsing CMS (Auth)EnvelopedData structures that use AEAD ciphers such as AES-GCM, the IV (Initialization Vector) encoded in the ASN.1 parameters is copied into a fixed-size stack buffer without verifying that its length fits the destination. An attacker can supply a crafted CMS message with an oversized IV, causing a stack-based out-of-bounds write before any authentication or tag verification occurs. Applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers (e.g., S/MIME (Auth)EnvelopedData with AES-GCM) are vulnerable. Because the overflow occurs prior to authentication, no valid key material is required to trigger it. While exploitability to remote code execution depends on platform and toolchain mitigations, the stack-based write primitive represents a severe risk. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the CMS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3 and 3.0 are vulnerable to this issue. OpenSSL 1.1.1 and 1.0.2 are not affected by this issue.

A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. This vulnerability affects TLS servers using PSK or ALPN callbacks across Node.js versions where these callbacks throw without being safely wrapped.

A memory leak in Node.js’s OpenSSL integration occurs when converting `X.509` certificate fields to UTF-8 without freeing the allocated buffer. When applications call `socket.getPeerCertificate(true)`, each certificate field leaks memory, allowing remote clients to trigger steady memory growth through repeated TLS connections. Over time this can lead to resource exhaustion and denial of service.

When doing SSH-based transfers using either SCP or SFTP, and asked to do public key authentication, curl would wrongly still ask and authenticate using a locally running SSH agent.

When doing SSH-based transfers using either SCP or SFTP, and setting the known_hosts file, libcurl could still mistakenly accept connecting to hosts *not present* in the specified file if they were added as recognized in the libssh *global* known_hosts file.

When doing TLS related transfers with reused easy or multi handles and altering the `CURLSSLOPT_NO_PARTIALCHAIN` option, libcurl could accidentally reuse a CA store cached in memory for which the partial chain option was reversed. Contrary to the user's wishes and expectations. This could make libcurl find and accept a trust chain that it otherwise would not.

When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a cross-protocol redirect to a second URL that uses an IMAP, LDAP, POP3 or SMTP scheme, curl might wrongly pass on the bearer token to the new target host.

When using `CURLOPT_PINNEDPUBLICKEY` option with libcurl or `--pinnedpubkey` with the curl tool,curl should check the public key of the server certificate to verify the peer. This check was skipped in a certain condition that would then make curl allow the connection without performing the proper check, thus not noticing a possible impostor. To skip this check, the connection had to be done with QUIC with ngtcp2 built to use GnuTLS and the user had to explicitly disable the standard certificate verification.

When doing multi-threaded LDAPS transfers (LDAP over TLS) with libcurl, changing TLS options in one thread would inadvertently change them globally and therefore possibly also affect other concurrently setup transfers. Disabling certificate verification for a specific transfer could unintentionally disable the feature for other threads as well.

The Uniffle HTTP client is configured to trust all SSL certificates and disables hostname verification by default. This insecure configuration exposes all REST API communication between the Uniffle CLI/client and the Uniffle Coordinator service to potential Man-in-the-Middle (MITM) attacks. This issue affects all versions from before 0.10.0. Users are recommended to upgrade to version 0.10.0, which fixes the issue.

A flaw was found in Keycloak. This vulnerability allows an unauthenticated remote attacker to cause a denial of service (DoS) by repeatedly initiating TLS 1.2 client-initiated renegotiation requests to exhaust server CPU resources, making the service unavailable.

A Stack-based buffer overflow vulnerability in the SonicOS SSLVPN service allows a remote unauthenticated attacker to cause Denial of Service (DoS), which could cause an impacted firewall to crash.

curl's code for managing SSH connections when SFTP was done using the wolfSSH powered backend was flawed and missed host verification mechanisms. This prevents curl from detecting MITM attackers and more.

When a client SSL profile is configured on a virtual server, undisclosed requests can cause an increase in memory resource utilization.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.

1. A cookie is set using the `secure` keyword for `https://target` 2. curl is redirected to or otherwise made to speak with `http://target` (same hostname, but using clear text HTTP) using the same cookie set 3. The same cookie name is set - but with just a slash as path (`path=\"/\",`). Since this site is not secure, the cookie *should* just be ignored. 4. A bug in the path comparison logic makes curl read outside a heap buffer boundary The bug either causes a crash or it potentially makes the comparison come to the wrong conclusion and lets the clear-text site override the contents of the secure cookie, contrary to expectations and depending on the memory contents immediately following the single-byte allocation that holds the path. The presumed and correct behavior would be to plainly ignore the second set of the cookie since it was already set as secure on a secure host so overriding it on an insecure host should not be okay.

curl's websocket code did not update the 32 bit mask pattern for each new outgoing frame as the specification says. Instead it used a fixed mask that persisted and was used throughout the entire connection. A predictable mask pattern allows for a malicious server to induce traffic between the two communicating parties that could be interpreted by an involved proxy (configured or transparent) as genuine, real, HTTP traffic with content and thereby poison its cache. That cached poisoned content could then be served to all users of that proxy.

In the Linux kernel, the following vulnerability has been resolved: tls: separate no-async decryption request handling from async If we're not doing async, the handling is much simpler. There's no reference counting, we just need to wait for the completion to wake us up and return its result. We should preferably also use a separate crypto_wait. I'm not seeing a UAF as I did in the past, I think aec7961916f3 ("tls: fix race between async notify and socket close") took care of it. This will make the next fix easier.

A vulnerability in the certificate processing of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper parsing of SSL/TLS certificates. An attacker could exploit this vulnerability by sending crafted DNS packets that match a static Network Address Translation (NAT) rule with DNS inspection enabled through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

The openssl crate before 0.10.55 for Rust allows an out-of-bounds read via an empty string to X509VerifyParamRef::set_host.

A heap-buffer-overread vulnerability was found in GnuTLS in how it handles the Certificate Transparency (CT) Signed Certificate Timestamp (SCT) extension during X.509 certificate parsing. This flaw allows a malicious user to create a certificate containing a malformed SCT extension (OID 1.3.6.1.4.1.11129.2.4.2) that contains sensitive data. This issue leads to the exposure of confidential information when GnuTLS verifies certificates from certain websites when the certificate (SCT) is not checked correctly.

A flaw was found in GnuTLS. A double-free vulnerability exists in GnuTLS due to incorrect ownership handling in the export logic of Subject Alternative Name (SAN) entries containing an otherName. If the type-id OID is invalid or malformed, GnuTLS will call asn1_delete_structure() on an ASN.1 node it does not own, leading to a double-free condition when the parent function or caller later attempts to free the same structure. This vulnerability can be triggered using only public GnuTLS APIs and may result in denial of service or memory corruption, depending on allocator behavior.

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

libcurl supports *pinning* of the server certificate public key for HTTPS transfers. Due to an omission, this check is not performed when connecting with QUIC for HTTP/3, when the TLS backend is wolfSSL. Documentation says the option works with wolfSSL, failing to specify that it does not for QUIC and HTTP/3. Since pinning makes the transfer succeed if the pin is fine, users could unwittingly connect to an impostor server without noticing.

Issue summary: Use of -addreject option with the openssl x509 application adds a trusted use instead of a rejected use for a certificate. Impact summary: If a user intends to make a trusted certificate rejected for a particular use it will be instead marked as trusted for that use. A copy & paste error during minor refactoring of the code introduced this issue in the OpenSSL 3.5 version. If, for example, a trusted CA certificate should be trusted only for the purpose of authenticating TLS servers but not for CMS signature verification and the CMS signature verification is intended to be marked as rejected with the -addreject option, the resulting CA certificate will be trusted for CMS signature verification purpose instead. Only users which use the trusted certificate format who use the openssl x509 command line application to add rejected uses are affected by this issue. The issues affecting only the command line application are considered to be Low severity. The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 3.4, 3.3, 3.2, 3.1, 3.0, 1.1.1 and 1.0.2 are also not affected by this issue.

A vulnerability in SMA100 allows a remote authenticated attacker with SSLVPN admin privileges can with admin privileges can inject shell command arguments to upload a file on the appliance.

A vulnerability in SMA100 allows a remote authenticated attacker with SSLVPN user privileges can inject a path traversal sequence to make any directory on the SMA appliance writable.

A vulnerability in SMA100 allows a remote authenticated attacker with SSLVPN user privileges to bypass the path traversal checks and delete an arbitrary file potentially resulting in a reboot to factory default settings.

An unauthenticated remote attacker could exploit the used, insecure TLS 1.0 and TLS 1.1 protocols to intercept and manipulate encrypted communications between the Com-Server and connected systems.

HCL MyXalytics is affected by SSL∕TLS Protocol affected with BREACH & LUCKY13 vulnerabilities. Attackers can exploit the weakness in the ciphers to intercept and decrypt encrypted data, steal sensitive information, or inject malicious code into the system.

In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation stating that it disables X11 and agent forwarding.

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

In the Linux kernel, the following vulnerability has been resolved: net/tls: fix slab-out-of-bounds bug in decrypt_internal The memory size of tls_ctx->rx.iv for AES128-CCM is 12 setting in tls_set_sw_offload(). The return value of crypto_aead_ivsize() for "ccm(aes)" is 16. So memcpy() require 16 bytes from 12 bytes memory space will trigger slab-out-of-bounds bug as following: ================================================================== BUG: KASAN: slab-out-of-bounds in decrypt_internal+0x385/0xc40 [tls] Read of size 16 at addr ffff888114e84e60 by task tls/10911 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report.cold+0x5e/0x5db ? decrypt_internal+0x385/0xc40 [tls] kasan_report+0xab/0x120 ? decrypt_internal+0x385/0xc40 [tls] kasan_check_range+0xf9/0x1e0 memcpy+0x20/0x60 decrypt_internal+0x385/0xc40 [tls] ? tls_get_rec+0x2e0/0x2e0 [tls] ? process_rx_list+0x1a5/0x420 [tls] ? tls_setup_from_iter.constprop.0+0x2e0/0x2e0 [tls] decrypt_skb_update+0x9d/0x400 [tls] tls_sw_recvmsg+0x3c8/0xb50 [tls] Allocated by task 10911: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 tls_set_sw_offload+0x2eb/0xa20 [tls] tls_setsockopt+0x68c/0x700 [tls] __sys_setsockopt+0xfe/0x1b0 Replace the crypto_aead_ivsize() with prot->iv_size + prot->salt_size when memcpy() iv value in TLS_1_3_VERSION scenario.

A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.

Issue summary: Clients using RFC7250 Raw Public Keys (RPKs) to authenticate a server may fail to notice that the server was not authenticated, because handshakes don't abort as expected when the SSL_VERIFY_PEER verification mode is set. Impact summary: TLS and DTLS connections using raw public keys may be vulnerable to man-in-middle attacks when server authentication failure is not detected by clients. RPKs are disabled by default in both TLS clients and TLS servers. The issue only arises when TLS clients explicitly enable RPK use by the server, and the server, likewise, enables sending of an RPK instead of an X.509 certificate chain. The affected clients are those that then rely on the handshake to fail when the server's RPK fails to match one of the expected public keys, by setting the verification mode to SSL_VERIFY_PEER. Clients that enable server-side raw public keys can still find out that raw public key verification failed by calling SSL_get_verify_result(), and those that do, and take appropriate action, are not affected. This issue was introduced in the initial implementation of RPK support in OpenSSL 3.2. The FIPS modules in 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

When libcurl is asked to perform automatic gzip decompression of content-encoded HTTP responses with the `CURLOPT_ACCEPT_ENCODING` option, **using zlib 1.2.0.3 or older**, an attacker-controlled integer overflow would make libcurl perform a buffer overflow.

libcurl would wrongly close the same eventfd file descriptor twice when taking down a connection channel after having completed a threaded name resolve.

When asked to use a `.netrc` file for credentials **and** to follow HTTP redirects, curl could leak the password used for the first host to the followed-to host under certain circumstances. This flaw only manifests itself if the netrc file has a `default` entry that omits both login and password. A rare circumstance.

An Improper Authentication vulnerability in the SSLVPN authentication mechanism allows a remote attacker to bypass authentication.

When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, curl could leak the password used for the first host to the followed-to host under certain circumstances. This flaw only manifests itself if the netrc file has an entry that matches the redirect target hostname but the entry either omits just the password or omits both login and password.

A vulnerability in the Transport Layer Security (TLS) protocol implementation of Cisco&nbsp;AsyncOS software for Cisco&nbsp;Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient processing of incoming TLS traffic. An attacker could exploit this vulnerability by sending a series of crafted TLS packets to an affected device. A successful exploit could allow the attacker to trigger a prolonged state of high CPU utilization. The affected device would still be operative, but response time and overall performance may be degraded.There are no workarounds that address this vulnerability.

A vulnerability in the SSL/TLS handler of Cisco&nbsp;Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause the affected device to reload unexpectedly, leading to a denial of service (DoS) condition. The vulnerability is due to improper error handling on established SSL/TLS connections. An attacker could exploit this vulnerability by establishing an SSL/TLS connection with the affected device and then sending a malicious SSL/TLS message within that connection. A successful exploit could allow the attacker to cause the device to reload.Cisco&nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Issue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, only applications that directly call the SSL_free_buffers function are affected by this issue. Applications that do not call this function are not vulnerable. Our investigations indicate that this function is rarely used by applications. The SSL_free_buffers function is used to free the internal OpenSSL buffer used when processing an incoming record from the network. The call is only expected to succeed if the buffer is not currently in use. However, two scenarios have been identified where the buffer is freed even when still in use. The first scenario occurs where a record header has been received from the network and processed by OpenSSL, but the full record body has not yet arrived. In this case calling SSL_free_buffers will succeed even though a record has only been partially processed and the buffer is still in use. The second scenario occurs where a full record containing application data has been received and processed by OpenSSL but the application has only read part of this data. Again a call to SSL_free_buffers will succeed even though the buffer is still in use. While these scenarios could occur accidentally during normal operation a malicious attacker could attempt to engineer a stituation where this occurs. We are not aware of this issue being actively exploited. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure `HTTP://` scheme and perform transfers with hosts like `x.example.com` as well as `example.com` where the first host is a subdomain of the second host. (The HSTS cache either needs to have been populated manually or there needs to have been previous HTTPS accesses done as the cache needs to have entries for the domains involved to trigger this problem.) When `x.example.com` responds with `Strict-Transport-Security:` headers, this bug can make the subdomain's expiry timeout *bleed over* and get set for the parent domain `example.com` in curl's HSTS cache. The result of a triggered bug is that HTTP accesses to `example.com` get converted to HTTPS for a different period of time than what was asked for by the origin server. If `example.com` for example stops supporting HTTPS at its expiry time, curl might then fail to access `http://example.com` until the (wrongly set) timeout expires. This bug can also expire the parent's entry *earlier*, thus making curl inadvertently switch back to insecure HTTP earlier than otherwise intended.

When curl is told to use the Certificate Status Request TLS extension, often referred to as OCSP stapling, to verify that the server certificate is valid, it might fail to detect some OCSP problems and instead wrongly consider the response as fine. If the returned status reports another error than 'revoked' (like for example 'unauthorized') it is not treated as a bad certficate.

Issue summary: Applications performing certificate name checks (e.g., TLS clients checking server certificates) may attempt to read an invalid memory address resulting in abnormal termination of the application process. Impact summary: Abnormal termination of an application can a cause a denial of service. Applications performing certificate name checks (e.g., TLS clients checking server certificates) may attempt to read an invalid memory address when comparing the expected name with an `otherName` subject alternative name of an X.509 certificate. This may result in an exception that terminates the application program. Note that basic certificate chain validation (signatures, dates, ...) is not affected, the denial of service can occur only when the application also specifies an expected DNS name, Email address or IP address. TLS servers rarely solicit client certificates, and even when they do, they generally don't perform a name check against a reference identifier (expected identity), but rather extract the presented identity after checking the certificate chain. So TLS servers are generally not affected and the severity of the issue is Moderate. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.