# CVE-2016-9775: Privilege escalation in n/a

> Local attackers with tomcat account access can gain root privileges by placing a setgid program in the Catalina directory.

- **Severity:** High 7.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Mar 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-5xvw-jhvw-hvp2, UBUNTU-CVE-2016-9775

## What is CVE-2016-9775?

CVE-2016-9775 is a high-severity vulnerability in Apache Tomcat, published on 23 Mar 2017. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The postrm script in the tomcat6 package before 6.0.45+dfsg-1~deb7u3 on Debian wheezy, before 6.0.45+dfsg-1~deb8u1 on Debian jessie, before 6.0.35-1ubuntu3.9 on Ubuntu 12.04 LTS and on Ubuntu 14.04 LTS; the tomcat7 package before 7.0.28-4+deb7u7 on Debian wheezy, before 7.0.56-3+deb8u6 on Debian jessie, before 7.0.52-1ubuntu0.8 on Ubuntu 14.04 LTS, and on Ubuntu 12.04 LTS, 16.04 LTS, and 16.10; and the tomcat8 package before 8.0.14-1+deb8u5 on Debian jessie, before 8.0.32-1ubuntu1.3 on Ubuntu 16.04 LTS, before 8.0.37-1ubuntu0.1 on Ubuntu 16.10, and before 8.0.38-2ubuntu1 on Ubuntu 17.04 might allow local users with access to the tomcat account to gain root privileges via a setgid program in the Catalina directory, as demonstrated by /etc/tomcat8/Catalina/attack.

Weakness: CWE-264

## Which versions are affected by CVE-2016-9775?

It affects 3 products.


Products: Apache Tomcat, Canonical Ubuntu Linux, Debian Debian Linux.

## How do I fix CVE-2016-9775?

Apply the vendor's patch.

## Is CVE-2016-9775 being exploited?

There is no known exploitation of CVE-2016-9775 in the wild and no public exploit code.

## Other vulnerabilities in Apache Tomcat

- [CVE-2025-24813](https://insights.sbomify.com/CVE-2025-24813/): Apache Tomcat Path Equivalence (critical 10.0, exploited in the wild)
- [CVE-2016-8735](https://insights.sbomify.com/CVE-2016-8735/): Apache Tomcat Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-12617](https://insights.sbomify.com/CVE-2017-12617/): Apache Tomcat Remote Code Execution (high 8.1, exploited in the wild)
- [CVE-2017-12615](https://insights.sbomify.com/CVE-2017-12615/): Apache Tomcat on Windows Remote Code Execution (high 8.1, exploited in the wild)
- [CVE-2026-34486](https://insights.sbomify.com/CVE-2026-34486/): Apache Tomcat Missing Encryption of Sensitive Data (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9775 and fix it if it is affected.

What it is: CVE-2016-9775 is a high-severity vulnerability in Apache Tomcat, published on 23 Mar 2017. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-9775 in the wild and no public exploit code.

Affected product: Apache Tomcat. 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-2016-9775/ (Markdown: https://insights.sbomify.com/CVE-2016-9775/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9775
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9775
- OSV: https://osv.dev/vulnerability/CVE-2016-9775

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-9775/
Summaries are generated and may contain mistakes; the official description above is the record.