CVE-2021-44733 Use after free in n/a

What is CVE-2021-44733?

CVE-2021-44733 is a high-severity use after free vulnerability in Debian Debian Linux, published on 22 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

Weakness: CWE-362

Which versions are affected by CVE-2021-44733?

It affects 12 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410c Firmware and 6 more.

How do I fix CVE-2021-44733?

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-2021-44733 being exploited?

There is no known exploitation of CVE-2021-44733 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 A-213173524, AZL-7063, DEBIAN-CVE-2021-44733, GHSA-4xqq-q6wp-w8h4, PUB-A-213173524, UBUNTU-CVE-2021-44733.