CVE-2021-37159 Use after free in n/a

What is CVE-2021-37159?

CVE-2021-37159 is a medium-severity use after free vulnerability in Debian Debian Linux, published on 21 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

hso_free_net_device in drivers/net/usb/hso.c in the Linux kernel through 5.13.4 calls unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free.

Weakness: CWE-416, CWE-415

Which versions are affected by CVE-2021-37159?

It affects 5 products.

Products include Debian Debian Linux, Linux kernel, Oracle Communications Cloud Native Core Binding Support Function, Oracle Communications Cloud Native Core Network Exposure Function, Oracle Communications Cloud Native Core Policy.

How do I fix CVE-2021-37159?

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-2021-37159 being exploited?

There is no known exploitation of CVE-2021-37159 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-195082947, AZL-6578, DEBIAN-CVE-2021-37159, GHSA-jh5h-88qq-m547, PUB-A-195082947, UBUNTU-CVE-2021-37159.