Debian Security Advisory

DLA-1846-1 unzip -- LTS security update

Date Reported:
07 Jul 2019
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 931433.
In Mitre's CVE dictionary: CVE-2019-13232.
More information:

David Fifield discovered a way to construct non-recursive zip bombs that achieve a high compression ratio by overlapping files inside the zip container. However the output size increases quadratically in the input size, reaching a compression ratio of over 28 million (10 MB -> 281 TB) at the limits of the zip format which can cause a denial-of-service. Mark Adler provided a patch to detect and reject such zip files for the unzip program.

For Debian 8 Jessie, this problem has been fixed in version 6.0-16+deb8u4.

We recommend that you upgrade your unzip packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: