CVE-2021-33913
libspf2 before 1.2.11 has a 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 SPF_record_expand_data in spf_expand.c. The amount of overflowed data depends on the relationship between the length of an entire domain name and the length of its leftmost label. 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.
EPSS 9.64% · 95.1th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:Pro:18.04:LTS | libspf2 | 0, 1.2.10-7build2 |
| Ubuntu:20.04:LTS | libspf2 | 0, 1.2.10-7build3, 1.2.10-7build4 |
| Ubuntu:Pro:16.04:LTS | libspf2 | 1.2.10-6ubuntu0.1~esm1, 1.2.10-6build1, 0 |
Timeline
- Jan 19, 2022 CVE Published
- Jan 20, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- May 6, 2022 EPSS Score
- Jun 29, 2022 EPSS Score
- Oct 14, 2022 EPSS Score
- Dec 6, 2022 EPSS Score
- Jan 28, 2023 EPSS Score
- Mar 22, 2023 EPSS Score
- May 15, 2023 EPSS Score
- Aug 29, 2023 EPSS Score
- Oct 21, 2023 EPSS Score
References
- https://ubuntu.com/security/CVE-2021-33913 third-party-advisory
- https://github.com/shevek/libspf2/commit/f06fef6cede4c4cb42f2c617496e6041782d7070 third-party-advisory
- https://ubuntu.com/security/notices/USN-6584-1 vendor-advisory
- https://ubuntu.com/security/notices/USN-6584-2 vendor-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-33913 third-party-advisory