CVE-2021-31870 Integer overflow in n/a

What is CVE-2021-31870?

CVE-2021-31870 is a critical 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. Multiplication in the calloc() function may result in an integer overflow and a subsequent heap buffer overflow.

Weakness: CWE-190

Which versions are affected by CVE-2021-31870?

It affects 2 products.

Products include Debian Debian Linux, Klibc Project Klibc.

How do I fix CVE-2021-31870?

Upgrade to a fixed version.

Is CVE-2021-31870 being exploited?

There is no known exploitation of CVE-2021-31870 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• 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-2021-31870, GHSA-q5g5-fc84-93h4, UBUNTU-CVE-2021-31870.