# CVE-2021-45909: gif2apng: An issue was discovered in gif2apng 1.9

CVE-2021-45909 is fixed in gif2apng on 1 platform, first by gif2apng 1.9+srconly-2ubuntu0.1, released December 27, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-45909
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0090
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 27, 2021

## Description

An issue was discovered in gif2apng 1.9. There is a 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | gif2apng Debian 11.6 (bullseye) | 1.9+srconly-3+deb11u1 | [DEBIAN-CVE-2021-45909](https://patchblox.com/security/data/fix/linux/debian-cve-2021-45909.md) | Dec 28, 2021 |
| Linux | gif2apng Ubuntu 18.04.6 LTS (bionic) | 1.9+srconly-2ubuntu0.1 | [gif2apng 1.9+srconly-2ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-gif2apng-1.9-srconly-2ubuntu0.1.md) | Dec 27, 2021 |
| Linux | gif2apng Ubuntu 20.04 LTS (focal) | 1.9+srconly-3ubuntu0.1 | [gif2apng 1.9+srconly-3ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-gif2apng-1.9-srconly-3ubuntu0.1.md) | Dec 27, 2021 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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