CVE-2021-33912
CRITICAL9.8EPSS 1.3%libspf2 - security update
Published: 1/19/2022Modified: 12/3/2025
Also known as:ALPINE-CVE-2021-33912
Description
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.
Affected packages (3)
- Alpine/libspf2from 0, < 1.2.11-r0
- Debian/libspf2from 0, < 1.2.10-7.1~deb11u1
- Debian/libspf2from 0, < 1.2.10-7+deb9u2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |