CVE-2021-23134 Linux kernel llcp_sock_bind/connect use-after-free

What is CVE-2021-23134?

CVE-2021-23134 is a high-severity use after free vulnerability in Debian Debian Linux, published on 12 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Use After Free vulnerability in nfc sockets in the Linux Kernel before 5.12.4 allows local attackers to elevate their privileges. In typical configurations, the issue can only be triggered by a privileged local user with the CAP_NET_RAW capability.

Weakness: CWE-416

Which versions are affected by CVE-2021-23134?

It affects 10 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Cloud Backup, Netapp H300s Firmware, Netapp H410c Firmware and 4 more.

How do I fix CVE-2021-23134?

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-2021-23134 being exploited?

There is no known exploitation of CVE-2021-23134 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 A-188883590, AZL-6531, DEBIAN-CVE-2021-23134, GHSA-jm36-c9r2-g7rq, PUB-A-188883590, UBUNTU-CVE-2021-23134.