# CVE-2015-8623: Cross-site request forgery in n/a

> Remote attackers can bypass CSRF protection in MediaWiki by guessing edit tokens via timing attacks due to non-constant time comparisons.

- **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:** 23 Mar 2017
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-8623, GHSA-8h72-c6mj-ffxx

## What is CVE-2015-8623?

CVE-2015-8623 is a high-severity vulnerability in Mediawiki Mediawiki, published on 23 Mar 2017. 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 User::matchEditToken function in includes/User.php in MediaWiki before 1.23.12 and 1.24.x before 1.24.5 does not perform token comparison in constant time before returning, which allows remote attackers to guess the edit token and bypass CSRF protection via a timing attack, a different vulnerability than CVE-2015-8624.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2015-8623?

It affects 1 product.


Products: Mediawiki Mediawiki.

## How do I fix CVE-2015-8623?

Upgrade to a fixed version.

## Is CVE-2015-8623 being exploited?

There is no known exploitation of CVE-2015-8623 in the wild and no public exploit code.

## Other vulnerabilities in Mediawiki Mediawiki

- [CVE-2023-37303](https://insights.sbomify.com/CVE-2023-37303/): Denial of service in n/a (critical 9.8)
- [CVE-2022-29904](https://insights.sbomify.com/CVE-2022-29904/): SQL injection in n/a (critical 9.8)
- [CVE-2022-29906](https://insights.sbomify.com/CVE-2022-29906/): Missing authorization in n/a (critical 9.8)
- [CVE-2022-28205](https://insights.sbomify.com/CVE-2022-28205/): Business logic in n/a (critical 9.8)
- [CVE-2022-28206](https://insights.sbomify.com/CVE-2022-28206/): Missing authorization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-8623 and fix it if it is affected.

What it is: CVE-2015-8623 is a high-severity vulnerability in Mediawiki Mediawiki, published on 23 Mar 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2015-8623 in the wild and no public exploit code.

Affected product: Mediawiki Mediawiki. 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-2015-8623/ (Markdown: https://insights.sbomify.com/CVE-2015-8623/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-8623
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-8623
- OSV: https://osv.dev/vulnerability/CVE-2015-8623

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-8623/
Summaries are generated and may contain mistakes; the official description above is the record.