Remote code execution in libspf2

1) Heap-based buffer overflow

EUVDB-ID: #VU85406

Risk: High

CVSSv4.0: 7.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-33912

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the SPF_record_expand_data() function in spf_expand.c. A remote attacker with control over a DNS server can create a specially crafted SPF DNS record, force the library to read data from the malicious DNS server, trigger a four-byte heap-based buffer overflow and execute arbitrary code on the system.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

libspf2: 1.0.2 - 1.2.10

CPE2.3

• cpe:2.3:a:gnome:libspf2:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:gnome:libspf2:1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:gnome:libspf2:1.0.4:*:*:*:*:*:*:*

External links

https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220b
https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosure
https://lists.debian.org/debian-lts-announce/2022/01/msg00015.html

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.