CVE-2021-31871 Integer overflow in n/a

What is CVE-2021-31871?

CVE-2021-31871 is a high-severity vulnerability in Debian Debian Linux, published on 30 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in klibc before 2.0.9. An integer overflow in the cpio command may result in a NULL pointer dereference on 64-bit systems.

Weakness: CWE-190

Which versions are affected by CVE-2021-31871?

It affects 2 products.

Products include Debian Debian Linux, Klibc Project Klibc.

How do I fix CVE-2021-31871?

Upgrade to a fixed version.

Is CVE-2021-31871 being exploited?

There is no known exploitation of CVE-2021-31871 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 DEBIAN-CVE-2021-31871, GHSA-xhrj-7pjg-g5cf, UBUNTU-CVE-2021-31871.