Back Linuxsecurity Ubuntu 25.10: klibc Critical Integer Arithmetic DoS USN-7959
A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 25.10 - Ubuntu 25.04 - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS - Ubuntu 14.04 LTS Summary: klibc could be made to crash if it received specially crafted input. Software Description: - klibc: Minimalistic libc subset for use with initramfs Details: It was discovered that zlib, vendored in klibc, did not properly handle integer arithmetic. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service.
A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 25.10 - Ubuntu 25.04 - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS - Ubuntu 14.04 LTS Summary: klibc could be made to crash if it received specially crafted input. Software Description: - klibc: Minimalistic libc subset for use with initramfs Details: It was discovered that zlib, vendored in klibc, did not properly handle integer arithmetic. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service.
The problem can be corrected by updating your system to the following package versions: Ubuntu 25.10 klibc-utils 2.0.14-1ubuntu1.1 libklibc 2.0.14-1ubuntu1.1 Ubuntu 25.04 klibc-utils 2.0.13-4ubuntu1.1 libklibc 2.0.13-4ubuntu1.1 Ubuntu 24.04 LTS klibc-utils 2.0.13-4ubuntu0.2 libklibc 2.0.13-4ubuntu0.2 Ubuntu 22.04 LTS klibc-utils 2.0.10-4ubuntu0.2 libklibc 2.0.10-4ubuntu0.2 Ubuntu 20.04 LTS klibc-utils 2.0.7-1ubuntu5.2+esm1 Available with Ubuntu Pro libklibc 2.0.7-1ubuntu5.2+esm1 Available with Ubuntu Pro Ubuntu 18.04 LTS klibc-utils 2.0.4-9ubuntu2.2+esm2 Available with Ubuntu Pro libklibc 2.0.4-9ubuntu2.2+esm2 Available with Ubuntu Pro Ubuntu 16.04 LTS klibc-utils 2.0.4-8ubuntu1.16.04.4+esm3 Available with Ubuntu Pro libklibc 2.0.4-8ubuntu1.16.04.4+esm3 Available with Ubuntu Pro Ubuntu 14.04 LTS klibc-utils 2.0.3-0ubuntu1.14.04.3+esm4 Available with Ubuntu Pro libklibc 2.0.3-0ubuntu1.14.04.3+esm4 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes.
The problem can be corrected by updating your system to the following package versions: Ubuntu 25.10 klibc-utils 2.0.14-1ubuntu1.1 libklibc 2.0.14-1ubuntu1.1 Ubuntu 25.04 klibc-utils 2.0.13-4ubuntu1.1 libklibc 2.0.13-4ubuntu1.1 Ubuntu 24.04 LTS klibc-utils 2.0.13-4ubuntu0.2 libklibc 2.0.13-4ubuntu0.2 Ubuntu 22.04 LTS klibc-utils 2.0.10-4ubuntu0.2 libklibc 2.0.10-4ubuntu0.2 Ubuntu 20.04 LTS klibc-utils 2.0.7-1ubuntu5.2+esm1 Available with Ubuntu Pro libklibc 2.0.7-1ubuntu5.2+esm1 Available with Ubuntu Pro Ubuntu 18.04 LTS klibc-utils 2.0.4-9ubuntu2.2+esm2 Available with Ubuntu Pro libklibc 2.0.4-9ubuntu2.2+esm2 Available with Ubuntu Pro Ubuntu 16.04 LTS klibc-utils 2.0.4-8ubuntu1.16.04.4+esm3 Available with Ubuntu Pro libklibc 2.0.4-8ubuntu1.16.04.4+esm3 Available with Ubuntu Pro Ubuntu 14.04 LTS klibc-utils 2.0.3-0ubuntu1.14.04.3+esm4 Available with Ubuntu Pro libklibc 2.0.3-0ubuntu1.14.04.3+esm4 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes.
The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
