#VU96964 Race condition in libarchive - CVE-2023-30571

Vulnerability identifier: #VU96964

Vulnerability risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-30571

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
libarchive
Client/Desktop applications / Software for archiving

Vendor: libarchive

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a race condition due to the umask() call inside archive_write_disk_posix.c changes the umask of the whole process for a very short period of time. Such a race condition could lead to implicit directory creation with permissions 0777 (without the sticky bit), which means that any low-privileged local user can delete and rename files inside those directories.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libarchive: 3.0 - 3.7.1

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External links
https://github.com/libarchive/libarchive/issues/1876
https://github.com/NixOS/nixpkgs/pull/244713

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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