# CVE-2018-18557: Memory corruption in n/a

> An out-of-bounds write in LibTIFF's JBIG decoder allows attackers to execute arbitrary code or cause denial of service when processing malicious images.

- **Severity:** High 8.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Oct 2018
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-18557, DEBIAN-CVE-2018-18557, GHSA-p963-j6qf-rp28, UBUNTU-CVE-2018-18557

## What is CVE-2018-18557?

CVE-2018-18557 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 22 Oct 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

LibTIFF 3.9.3, 3.9.4, 3.9.5, 3.9.6, 3.9.7, 4.0.0alpha4, 4.0.0alpha5, 4.0.0alpha6, 4.0.0beta7, 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.0.4beta, 4.0.5, 4.0.6, 4.0.7, 4.0.8 and 4.0.9 (with JBIG enabled) decodes arbitrarily-sized JBIG into a buffer, ignoring the buffer size, which leads to a tif_jbig.c JBIGDecode out-of-bounds write.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2018-18557?

It affects 3 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Libtiff Libtiff.

## How do I fix CVE-2018-18557?

Apply the vendor's patch.

## Is CVE-2018-18557 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-18557 exists.

Public exploit code:

- libtiff 4.0.9 - Decodes Arbitrarily Sized JBIG into a Target Buffer (exploitdb)

## 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-2018-18557 and fix it if it is affected.

What it is: CVE-2018-18557 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 22 Oct 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-18557 exists.

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-2018-18557/ (Markdown: https://insights.sbomify.com/CVE-2018-18557/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18557
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18557
- OSV: https://osv.dev/vulnerability/CVE-2018-18557

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18557/
Summaries are generated and may contain mistakes; the official description above is the record.