Buffer overflow in Libspf2 Project
CVE-2021-33912
libspf2 before 1.2.11 has a four-byte heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of incorrect sprintf usage in SPF_record_expand_data in spf_expand.c. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.
Vulnerability class: Buffer Overflow
EPSS: 0.096 (95.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Libspf2_project Libspf2
- Debian Debian_linux — versions 9.0
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org (Exploit, Third Party Advisory)
- cve@mitre.org (mailing-list, Mailing List, Third Party Advisory)
- cve@mitre.org (vendor-advisory)
Frequently asked questions
- What is CVE-2021-33912?
- CVE-2021-33912 is a critical-severity vulnerability in Libspf2 Project, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2022-01-19.
- How severe is CVE-2021-33912?
- Critical severity. CVSS v3 base score is 9.8 out of 10.