CVE-2020-9273 Use after free in n/a

What is CVE-2020-9273?

CVE-2020-9273 is a high-severity use after free vulnerability in Debian Debian Linux, published on 20 Feb 2020. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

In ProFTPD 1.3.7, it is possible to corrupt the memory pool by interrupting the data transfer channel. This triggers a use-after-free in alloc_pool in pool.c, and possible remote code execution.

Weakness: CWE-416

Which versions are affected by CVE-2020-9273?

It affects 7 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Opensuse Backports Sle, Opensuse Leap, Proftpd Proftpd, Siemens Simatic Net Cp 1543-1 Firmware and 1 more.

How do I fix CVE-2020-9273?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2020-9273 being exploited?

There is no known exploitation of CVE-2020-9273 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

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 DEBIAN-CVE-2020-9273, DLA-2115-1, DLA-2115-2, DSA-4635-1, GHSA-j879-hg9w-v5qv, MGASA-2020-0120 and 1 more.