# CVE-2010-0166: Memory corruption in n/a

> Remote attackers can execute arbitrary code or cause denial of service via crafted HTML with invisible Unicode characters in Firefox on Mac OS X.

- **Severity:** Medium 5.1 (`AV:N/AC:H/Au:N/C:P/I:P/A:P`)
- **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:** 25 Mar 2010
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-g5x4-8v96-9hwx

## What is CVE-2010-0166?

CVE-2010-0166 is a medium-severity memory corruption vulnerability in Mozilla Firefox, published on 25 Mar 2010. 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

The gfxTextRun::SanitizeGlyphRuns function in gfx/thebes/src/gfxFont.cpp in the browser engine in Mozilla Firefox 3.6 before 3.6.2 on Mac OS X, when the Core Text API is used, does not properly perform certain deletions, which allows remote attackers to cause a denial of service (memory corruption and application crash) and possibly execute arbitrary code via an HTML document containing invisible Unicode characters, as demonstrated by the U+FEFF, U+FFF9, U+FFFA, and U+FFFB characters.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2010-0166?

It affects 1 product.


Products: Mozilla Firefox.

## How do I fix CVE-2010-0166?

Upgrade to a fixed version.

## Is CVE-2010-0166 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2010-0166 exists.

Public exploit code:

- Mozilla Firefox 3.6 - 'gfxTextRun::SanitizeGlyphRuns()' Remote Memory Corruption (exploitdb)

## Other vulnerabilities in Mozilla Firefox

- [CVE-2019-11708](https://insights.sbomify.com/CVE-2019-11708/): Mozilla Firefox and Thunderbird Sandbox Escape (critical 10.0, exploited in the wild)
- [CVE-2010-3765](https://insights.sbomify.com/CVE-2010-3765/): Mozilla Multiple Products Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-26486](https://insights.sbomify.com/CVE-2022-26486/): Mozilla Firefox Use-After-Free (critical 9.6, exploited in the wild)
- [CVE-2022-26485](https://insights.sbomify.com/CVE-2022-26485/): Mozilla Firefox Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2019-11707](https://insights.sbomify.com/CVE-2019-11707/): Mozilla Firefox and Thunderbird Type Confusion (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2010-0166 and fix it if it is affected.

What it is: CVE-2010-0166 is a medium-severity memory corruption vulnerability in Mozilla Firefox, published on 25 Mar 2010. 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-2010-0166 exists.

Affected product: Mozilla Firefox. 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-2010-0166/ (Markdown: https://insights.sbomify.com/CVE-2010-0166/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2010-0166
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2010-0166
- OSV: https://osv.dev/vulnerability/CVE-2010-0166

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From sbomify Insights: https://insights.sbomify.com/CVE-2010-0166/
Summaries are generated and may contain mistakes; the official description above is the record.