Debian Security Advisory

DLA-2937-1 gif2apng -- LTS security update

Date Reported:
07 Mar 2022
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2021-45909, CVE-2021-45910, CVE-2021-45911.
More information:

Three issues have been discovered in gif2apng: tool for converting animated GIF images to APNG format.

  • CVE-2021-45909

    heap-based buffer overflow vulnerability in the DecodeLZW function. It allows an attacker to write a large amount of arbitrary data outside the boundaries of a buffer.

  • CVE-2021-45910:

    heap-based buffer overflow within the main function. It allows an attacker to write data outside of the allocated buffer.

  • CVE-2021-45911:

    heap based buffer overflow in processing of delays in the main function.

For Debian 9 stretch, these problems have been fixed in version 1.9+srconly-2+deb9u2.

We recommend that you upgrade your gif2apng packages.

For the detailed security status of gif2apng please refer to its security tracker page at:

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