CVE-2024-7589

Published Aug 12, 2024

Last updated 2 years ago

CVSS high 8.1
SSH
Tunneling protocol
Port (22)

Overview

Description
A signal handler in sshd(8) may call a logging function that is not async-signal-safe. The signal handler is invoked when a client does not authenticate within the LoginGraceTime seconds (120 by default). This signal handler executes in the context of the sshd(8)'s privileged code, which is not sandboxed and runs with full root privileges. This issue is another instance of the problem in CVE-2024-6387 addressed by FreeBSD-SA-24:04.openssh. The faulty code in this case is from the integration of blacklistd in OpenSSH in FreeBSD. As a result of calling functions that are not async-signal-safe in the privileged sshd(8) context, a race condition exists that a determined attacker may be able to exploit to allow an unauthenticated remote code execution as root.
Source
secteam@freebsd.org
NVD status
Analyzed
Products
freebsd

Risk scores

CVSS 3.1

Type
Primary
Base score
8.1
Impact score
5.9
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-362
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-364

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. When copying knotes from a parent kqueue to a child, the copy code did not correctly exclude marker knotes (used internally to track list traversal position) before marking them as in-flux and releasing the kqueue lock. If another thread freed a marker while the lock was dropped, the subsequent in-flux decrement operated on freed memory. An unprivileged local user may be able to exploit these races to escalate privileges.•CVE-2026-58099
  2. When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds. An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.•CVE-2026-58098
  3. kqueue_fork_copy_knote() indexed into the child's file descriptor table using a knote's file descriptor number without a bounds check. Because the child's table is copied before knotes are transferred, a concurrent thread in the parent could grow the parent's table and register knotes with file descriptor numbers beyond the end of the child's table, causing an out-of-bounds read. An unprivileged local user may be able to exploit these races to escalate privileges.•CVE-2026-58100
  4. When an audio channel's buffer needs to be resized, the sound(4) driver checks that the buffer is not memory-mapped and then drops the channel lock to allocate a new buffer. An mmap(2) call on another thread can complete during this window, after which the resize path frees the now-mapped buffer without rechecking. An unprivileged local user with access to a sound device can exploit this race to trigger a use-after-free in the kernel, potentially escalating privileges.•CVE-2026-101308
  5. renameat(2) did not enforce FD_RESOLVE_BENEATH on its directory arguments. A jailed process could rename a directory relative to a restricted descriptor, then escape the jail root via fchdir(2). This requires the directory to reside on a filesystem that is also reachable from the jail's root. A process in a jail that has received a directory file descriptor from another jail can use these techniques to escape the jail's filesystem root restriction.•CVE-2026-101305

References

Sources include official advisories and independent security research.