# CVE-2016-8900: Deserialization in n/a

> An object injection vulnerability in Exponent CMS allows attackers to execute arbitrary code via the change_tags function.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 24 May 2019
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-rw5c-588j-g4qf

## What is CVE-2016-8900?

CVE-2016-8900 is a critical unsafe deserialization vulnerability in Exponentcms Exponent Cms, published on 24 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Exponent CMS version 2.3.9 suffers from a Object Injection vulnerability in framework/modules/core/controllers/expTagController.php related to change_tags.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2016-8900?

It affects 1 product.


Products: Exponentcms Exponent Cms.

## How do I fix CVE-2016-8900?

No fix has been published for CVE-2016-8900 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-8900 being exploited?

There is no known exploitation of CVE-2016-8900 in the wild and no public exploit code.

## Other vulnerabilities in Exponentcms Exponent Cms

- [CVE-2016-9021](https://insights.sbomify.com/CVE-2016-9021/): Exponent CMS before 2.6.0 has improper input validation in storeController.php. (critical 9.8)
- [CVE-2016-9022](https://insights.sbomify.com/CVE-2016-9022/): Other in n/a (critical 9.8)
- [CVE-2016-9023](https://insights.sbomify.com/CVE-2016-9023/): Other in n/a (critical 9.8)
- [CVE-2016-9025](https://insights.sbomify.com/CVE-2016-9025/): Other in n/a (critical 9.8)
- [CVE-2016-9026](https://insights.sbomify.com/CVE-2016-9026/): File upload in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-8900 and fix it if it is affected.

What it is: CVE-2016-8900 is a critical unsafe deserialization vulnerability in Exponentcms Exponent Cms, published on 24 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-8900 in the wild and no public exploit code.

Affected product: Exponentcms Exponent Cms. 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-2016-8900/ (Markdown: https://insights.sbomify.com/CVE-2016-8900/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-8900
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-8900
- OSV: https://osv.dev/vulnerability/CVE-2016-8900

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-8900/
Summaries are generated and may contain mistakes; the official description above is the record.