CVE-2021-43303 Memory corruption in pjsip

What is CVE-2021-43303?

CVE-2021-43303 is a critical memory corruption vulnerability in Debian Debian Linux, published on 16 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Buffer overflow in PJSUA API when calling pjsua_call_dump. An attacker-controlled 'buffer' argument may cause a buffer overflow, since supplying an output buffer smaller than 128 characters may overflow the output buffer, regardless of the 'maxlen' argument supplied

Weakness: CWE-120

Which versions are affected by CVE-2021-43303?

It affects 2 products.

Products include Debian Debian Linux, Teluu Pjsip.

How do I fix CVE-2021-43303?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-43303 being exploited?

There is no known exploitation of CVE-2021-43303 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2021-43303, DEBIAN-CVE-2021-43303, GHSA-f7jc-p66f-75xp, UBUNTU-CVE-2021-43303.