#VU66757 Use-after-free in systemd - CVE-2022-2526

Vulnerability identifier: #VU66757

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-2526

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
systemd
Server applications / Other server solutions

Vendor: Freedesktop.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the on_stream_io() and dns_stream_complete() functions in resolved-dns-stream.c, which do not increment the reference counting for the DnsStream object. A remote attacker can send to the system specially crafted DNS responses, trigger a use-after-free error and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

systemd: 200 - 239

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External links
https://github.com/systemd/systemd/commit/d973d94dec349fb676fdd844f6fe2ada3538f27c
https://bugzilla.redhat.com/show_bug.cgi?id=2109926

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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.