# CVE-2020-29385: Denial of service in n/a

> An attacker can cause a denial of service via an infinite loop in the LZW decoder by providing a specially crafted GIF image to applications using GDK Pixbuf.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 26 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2020-29385, DEBIAN-CVE-2020-29385, GHSA-wf85-g3p6-xf4h, SUSE-SU-2021:0184-1, UBUNTU-CVE-2020-29385, USN-4663-1, openSUSE-SU-2021:0150-1

## What is CVE-2020-29385?

CVE-2020-29385 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 26 Dec 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

GNOME gdk-pixbuf (aka GdkPixbuf) before 2.42.2 allows a denial of service (infinite loop) in lzw.c in the function write_indexes. if c->self_code equals 10, self->code_table[10].extends will assign the value 11 to c. The next execution in the loop will assign self->code_table[11].extends to c, which will give the value of 10. This will make the loop run infinitely. This bug can, for example, be triggered by calling this function with a GIF image with LZW compression that is crafted in a special way.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2020-29385?

It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `gdk-pixbuf` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 2.40.0-3.3.1 |
| `gdk-pixbuf` | SUSE:Linux Enterprise Module for Desktop Applications 15 SP2 | All versions | 2.40.0-3.3.1 |
| `gdk-pixbuf` | openSUSE:Leap 15.2 | All versions | 2.40.0-lp152.2.3.1 |

Products: Canonical Ubuntu Linux, Fedoraproject Fedora, Gnome Gdk-Pixbuf.

## How do I fix CVE-2020-29385?

Upgrade to a fixed version.

## Is CVE-2020-29385 being exploited?

There is no known exploitation of CVE-2020-29385 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-29385 and fix it if it is affected.

What it is: CVE-2020-29385 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 26 Dec 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-29385 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-29385/ (Markdown: https://insights.sbomify.com/CVE-2020-29385/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29385
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29385
- OSV: https://osv.dev/vulnerability/CVE-2020-29385

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-29385/
Summaries are generated and may contain mistakes; the official description above is the record.