TLS vulnerabilities

OpenSSL 0.9.8f and 0.9.8g allows remote attackers to cause a denial of service (crash) via a TLS handshake that omits the Server Key Exchange message and uses "particular cipher suites," which triggers a NULL pointer dereference.

Double free vulnerability in OpenSSL 0.9.8f and 0.9.8g, when the TLS server name extensions are enabled, allows remote attackers to cause a denial of service (crash) via a malformed Client Hello packet. NOTE: some of these details are obtained from third party information.

OpenSSL 0.9.8c-1 up to versions before 0.9.8g-9 on Debian-based operating systems uses a random number generator that generates predictable numbers, which makes it easier for remote attackers to conduct brute force guessing attacks against cryptographic keys.

OpenSSH 4.4 up to versions before 4.9 allows remote authenticated users to bypass the sshd_config ForceCommand directive by modifying the .ssh/rc session file.

OpenSSH 4.3p2, and probably other versions, allows local users to hijack forwarded X connections by causing ssh to set DISPLAY to :10, even when another process is listening on the associated port, as demonstrated by opening TCP port 6010 (IPv4) and sniffing a cookie sent by Emacs.

Unspecified vulnerability in the linux_audit_record_event function in OpenSSH 4.3p2, as used on Fedora Core 6 and possibly other systems, allows remote attackers to write arbitrary characters to an audit log via a crafted username. NOTE: some of these details are obtained from third party information.

Off-by-one error in the DTLS implementation in OpenSSL 0.9.8 before 0.9.8f allows remote attackers to execute arbitrary code via unspecified vectors.

Off-by-one error in the SSL_get_shared_ciphers function in OpenSSL 0.9.7 up to 0.9.7l, and 0.9.8 up to 0.9.8f, might allow remote attackers to execute arbitrary code via a crafted packet that triggers a one-byte buffer underflow. NOTE: this issue was introduced as a result of a fix for CVE-2006-3738. As of 20071012, it is unknown whether code execution is possible.

ssh in OpenSSH before 4.7 does not properly handle when an untrusted cookie cannot be created and uses a trusted X11 cookie instead, which allows attackers to violate intended policy and gain privileges by causing an X client to be treated as trusted.

Unspecified vulnerability in SSHield 1.6.1 with OpenSSH 3.0.2p1 on Cisco WebNS 8.20.0.1 on Cisco Content Services Switch (CSS) series 11000 devices allows remote attackers to cause a denial of service (connection slot exhaustion and device crash) via a series of large packets designed to exploit the SSH CRC32 attack detection overflow (CVE-2001-0144), possibly a related issue to CVE-2002-1024.

The BN_from_montgomery function in crypto/bn/bn_mont.c in OpenSSL 0.9.8e and earlier does not properly perform Montgomery multiplication, which might allow local users to conduct a side-channel attack and retrieve RSA private keys.

libcurl 7.14.0 through 7.16.3, when built with GnuTLS support, does not check SSL/TLS certificate expiration or activation dates, which allows remote attackers to bypass certain access restrictions.

OpenSSH, when using OPIE (One-Time Passwords in Everything) for PAM, allows remote attackers to determine the existence of certain user accounts, which displays a different response if the user account exists and is configured to use one-time passwords (OTP), a similar issue to CVE-2007-2243.

OpenSSH 4.6 and earlier, when ChallengeResponseAuthentication is enabled, allows remote attackers to determine the existence of user accounts by attempting to authenticate via S/KEY, which displays a different response if the user account exists, a similar issue to CVE-2001-1483.

Unspecified vulnerability in the sshd Privilege Separation Monitor in OpenSSH before 4.5 causes weaker verification that authentication has been successful, which might allow attackers to bypass authentication. NOTE: as of 20061108, it is believed that this issue is only exploitable by leveraging vulnerabilities in the unprivileged process, which are not known to exist.

OpenSSH portable 4.1 on SUSE Linux, and possibly other platforms and versions, and possibly under limited configurations, allows remote attackers to determine valid usernames via timing discrepancies in which responses take longer for valid usernames than invalid ones, as demonstrated by sshtime. NOTE: as of 20061014, it appears that this issue is dependent on the use of manually-set passwords that causes delays when processing /etc/shadow due to an increased number of rounds.

packet.c in ssh in OpenSSH allows remote attackers to cause a denial of service (crash) by sending an invalid protocol sequence with USERAUTH_SUCCESS before NEWKEYS, which causes newkeys[mode] to be NULL.

The get_server_hello function in the SSLv2 client code in OpenSSL 0.9.7 before 0.9.7l, 0.9.8 before 0.9.8d, and earlier versions allows remote servers to cause a denial of service (client crash) via unknown vectors that trigger a null pointer dereference.

Buffer overflow in the SSL_get_shared_ciphers function in OpenSSL 0.9.7 before 0.9.7l, 0.9.8 before 0.9.8d, and earlier versions has unspecified impact and remote attack vectors involving a long list of ciphers.

OpenSSL 0.9.7 before 0.9.7l, 0.9.8 before 0.9.8d, and earlier versions allows attackers to cause a denial of service (CPU consumption) via parasitic public keys with large (1) "public exponent" or (2) "public modulus" values in X.509 certificates that require extra time to process when using RSA signature verification.

OpenSSL 0.9.7 before 0.9.7l and 0.9.8 before 0.9.8d allows remote attackers to cause a denial of service (infinite loop and memory consumption) via malformed ASN.1 structures that trigger an improperly handled error condition.

Unspecified vulnerability in portable OpenSSH before 4.4, when running on some platforms, allows remote attackers to determine the validity of usernames via unknown vectors involving a GSSAPI "authentication abort."

Signal handler race condition in OpenSSH before 4.4 allows remote attackers to cause a denial of service (crash), and possibly execute arbitrary code if GSSAPI authentication is enabled, via unspecified vectors that lead to a double-free.

sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.

OpenSSL before 0.9.7, 0.9.7 before 0.9.7k, and 0.9.8 before 0.9.8c, when using an RSA key with exponent 3, removes PKCS-1 padding before generating a hash, which allows remote attackers to forge a PKCS #1 v1.5 signature that is signed by that RSA key and prevents OpenSSL from correctly verifying X.509 and other certificates that use PKCS #1.

Heap-based buffer overflow in cURL and libcURL 7.15.0 through 7.15.2 allows remote attackers to execute arbitrary commands via a TFTP URL (tftp://) with a valid hostname and a long path.

OpenSSH on FreeBSD 5.3 and 5.4, when used with OpenPAM, does not properly handle when a forked child process terminates during PAM authentication, which allows remote attackers to cause a denial of service (client connection refusal) by connecting multiple times to the SSH server, waiting for the password prompt, then disconnecting.

scp in OpenSSH 4.2p1 allows attackers to execute arbitrary commands via filenames that contain shell metacharacters or spaces, which are expanded twice.

Multiple off-by-one errors in the cURL library (libcurl) 7.11.2 through 7.15.0 allow local users to trigger a buffer overflow and cause a denial of service or bypass PHP security restrictions via certain URLs that (1) are malformed in a way that prevents a terminating null byte from being added to either a hostname or path buffer, or (2) contain a "?" separator in the hostname portion, which causes a "/" to be prepended to the resulting string.

The SSL/TLS server implementation in OpenSSL 0.9.7 before 0.9.7h and 0.9.8 before 0.9.8a, when using the SSL_OP_MSIE_SSLV2_RSA_PADDING option, disables a verification step that is required for preventing protocol version rollback attacks, which allows remote attackers to force a client and server to use a weaker protocol than needed via a man-in-the-middle attack.

Stack-based buffer overflow in the ntlm_output function in http-ntlm.c for (1) wget 1.10, (2) curl 7.13.2, and (3) libcurl 7.13.2, and other products that use libcurl, when NTLM authentication is enabled, allows remote servers to execute arbitrary code via a long NTLM username.

The default configuration on OpenSSL before 0.9.8 uses MD5 for creating message digests instead of a more cryptographically strong algorithm, which makes it easier for remote attackers to forge certificates with a valid certificate authority signature.

sshd in OpenSSH before 4.2, when GSSAPIDelegateCredentials is enabled, allows GSSAPI credentials to be delegated to clients who log in using non-GSSAPI methods, which could cause those credentials to be exposed to untrusted users or hosts.

OpenSSH 4.0, and other versions before 4.2, does not properly handle dynamic port forwarding ("-D" option) when a listen address is not provided, which may cause OpenSSH to enable the GatewayPorts functionality.

SSH, as implemented in OpenSSH before 4.0 and possibly other implementations, stores hostnames, IP addresses, and keys in plaintext in the known_hosts file, which makes it easier for an attacker that has compromised an SSH user's account to generate a list of additional targets that are more likely to have the same password or key.

The design of Advanced Encryption Standard (AES), aka Rijndael, allows remote attackers to recover AES keys via timing attacks on S-box lookups, which are difficult to perform in constant time in AES implementations.

Multiple stack-based buffer overflows in libcURL and cURL 7.12.1, and possibly other versions, allow remote malicious web servers to execute arbitrary code via base64 encoded replies that exceed the intended buffer lengths when decoded, which is not properly handled by (1) the Curl_input_ntlm function in http_ntlm.c during NTLM authentication or (2) the Curl_krb_kauth and krb4_auth functions in krb4.c during Kerberos authentication.

The der_chop script in the openssl package in Trustix Secure Linux 1.5 through 2.1 and other operating systems allows local users to overwrite files via a symlink attack on temporary files.

sshd in OpenSSH 3.5p1, when PermitRootLogin is disabled, immediately closes the TCP connection after a root login attempt with the correct password, but leaves the connection open after an attempt with an incorrect password, which makes it easier for remote attackers to guess the password by observing the connection state, a different vulnerability than CVE-2003-0190. NOTE: it could be argued that in most environments, this does not cross privilege boundaries without requiring leverage of a separate vulnerability.

sshd.c in OpenSSH 3.6.1p2 and 3.7.1p2 and possibly other versions, when using privilege separation, does not properly signal the non-privileged process when a session has been terminated after exceeding the LoginGraceTime setting, which leaves the connection open and allows remote attackers to cause a denial of service (connection consumption).

The SSL/TLS handshaking code in OpenSSL 0.9.7a, 0.9.7b, and 0.9.7c, when using Kerberos ciphersuites, does not properly check the length of Kerberos tickets during a handshake, which allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that causes an out-of-bounds read.

OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

The default configuration for OpenSSH enables AllowTcpForwarding, which could allow remote authenticated users to perform a port bounce, when configured with an anonymous access program such as AnonCVS.

Directory traversal vulnerability in scp for OpenSSH before 3.4p1 allows remote malicious servers to overwrite arbitrary files. NOTE: this may be a rediscovery of CVE-2000-0992.

sshd in OpenSSH 3.6.1p2 and earlier, when PermitRootLogin is disabled and using PAM keyboard-interactive authentication, does not insert a delay after a root login attempt with the correct password, which makes it easier for remote attackers to use timing differences to determine if the password step of a multi-step authentication is successful, a different vulnerability than CVE-2003-0190.

OpenSSL 0.9.6k allows remote attackers to cause a denial of service (crash via large recursion) via malformed ASN.1 sequences.

The PAM conversation function in OpenSSH 3.7.1 and 3.7.1p1 interprets an array of structures as an array of pointers, which allows attackers to modify the stack and possibly gain privileges.

The SSH1 PAM challenge response authentication in OpenSSH 3.7.1 and 3.7.1p1, when Privilege Separation is disabled, does not check the result of the authentication attempt, which can allow remote attackers to gain privileges.

Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via an SSL client certificate with a certain invalid ASN.1 encoding.