Last updated 2 June 2026

Last updated 4 August 2025

An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of crafted file.

References:

https://tukaani.org/xz/ https://github.com/snappyJack/CVE-request-XZ-5.2.5-has-denial-of-service-vulnerability

DISPUTED An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafted file. NOTE: the vendor disputes the claims of "endless output" and "denial of service" because decompression of the 17,486 bytes always results in 114,881,179 bytes, which is often a reasonable size increase.

An arbitrary file write vulnerability was found in GNU gzip's zgrep utility. When zgrep is applied on the attacker's chosen file name (for example, a crafted file name), this can overwrite an attacker's content to an arbitrary attacker-selected file. This flaw occurs due to insufficient validation when processing filenames with two or more newlines where selected content and the target file names are embedded in crafted multi-line file names. This flaw allows a remote, low privileged attacker to force zgrep to write arbitrary files on the system.

It was found that xzgrep did not correctly process file names containing a semicolon. A local attacker able to trick a user to run xzgrep on a specially crafted file could use this flaw to execute arbitrary code as the user running xzgrep.

$ touch /tmp/semi\;colon $ xzgrep anystring /tmp/semi\;colon xz: /tmp/semi: No such file or directory /usr/bin/xzgrep: line 199: colon: command not found

Additional details:

http://seclists.org/oss-sec/2015/q2/484