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.
The product writes data past the end, or before the beginning, of the intended buffer.
| Link | Tags |
|---|---|
| https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220b | third party advisory |
| https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosure | third party advisory exploit |
| https://lists.debian.org/debian-lts-announce/2022/01/msg00015.html | third party advisory mailing list |
| https://security.gentoo.org/glsa/202401-22 | vendor advisory |