CVE-2021-33912 Memory corruption in n/a
Remote attackers can execute arbitrary code via crafted SPF DNS records due to a heap buffer overflow in libspf2, affecting mail infrastructure using this library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-33912?
CVE-2021-33912 is a critical memory corruption vulnerability in Debian Debian Linux, published on 19 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-787
Which versions are affected by CVE-2021-33912?
It affects 2 products.
Products include Debian Debian Linux, Libspf2 Project Libspf2.
How do I fix CVE-2021-33912?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-33912 being exploited?
There is no known exploitation of CVE-2021-33912 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2021-33912, DEBIAN-CVE-2021-33912, GHSA-f8wp-q2v8-9hc2, UBUNTU-CVE-2021-33912.