Red Hat Enterprise Linux 9 update for openssh

1) Race condition

EUVDB-ID: #VU94522

Risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2024-6409

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to a race condition in portable version of sshd when handling signals. If a remote attacker does not authenticate within a set time period, then sshd's SIGALRM handler is called asynchronously. A remote non-authenticated attacker can send a series of requests in order to trigger a race condition and execute arbitrary code on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for ARM 64: 9

Red Hat Enterprise Linux for Power, little endian: 9

Red Hat Enterprise Linux for IBM z Systems: 9

Red Hat Enterprise Linux for x86_64: 9

openssh (Red Hat package): before 8.7p1-38.el9_4.4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:9:*:*:*:*:red_hat_enterprise_linux:*:
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:9:*:*:*:*:red_hat_enterprise_linux:*:
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:9:*:*:*:*:red_hat_enterprise_linux:*:
• cpe:2.3:o:red_hat:red_hat_enterprise_linux:9:*:*:*:*:*:*:

External links

http://access.redhat.com/errata/RHSA-2024:4457

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.