# CVE-2017-16858: Auth bypass in Crowd

> Attackers can impersonate users across directories in Atlassian Crowd by exploiting authentication flaws in the crowd-application plugin, requiring specific directory bindings.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Jan 2018
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-p3gx-g437-gw6c

## What is CVE-2017-16858?

CVE-2017-16858 is a medium-severity authentication bypass vulnerability in Atlassian Crowd, published on 31 Jan 2018. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The 'crowd-application' plugin module (notably used by the Google Apps plugin) in Atlassian Crowd from version 1.5.0 before version 3.1.2 allowed an attacker to impersonate a Crowd user in REST requests by being able to authenticate to a directory bound to an application using the feature. Given the following situation: the Crowd application is bound to directory 1 and has a user called admin and the Google Apps application is bound to directory 2, which also has a user called admin, it was possible to authenticate REST requests using the credentials of the user coming from directory 2 and impersonate the user from directory 1.

Weakness: CWE-287 (Improper Authentication), CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2017-16858?

It affects 1 product.


Products: Atlassian Crowd.

## How do I fix CVE-2017-16858?

No fix has been published for CVE-2017-16858 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-16858 being exploited?

There is no known exploitation of CVE-2017-16858 in the wild and no public exploit code.

## Other vulnerabilities in Atlassian Crowd

- [CVE-2019-11580](https://insights.sbomify.com/CVE-2019-11580/): Atlassian Crowd and Crowd Data Center Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-43782](https://insights.sbomify.com/CVE-2022-43782/): Auth bypass in Crowd Data Center (critical 9.8)
- [CVE-2016-6496](https://insights.sbomify.com/CVE-2016-6496/): Deserialization in n/a (critical 9.8)
- [CVE-2017-18105](https://insights.sbomify.com/CVE-2017-18105/): Auth bypass in Crowd (high 8.1)
- [CVE-2018-20238](https://insights.sbomify.com/CVE-2018-20238/): Auth bypass in Crowd (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-16858 and fix it if it is affected.

What it is: CVE-2017-16858 is a medium-severity authentication bypass vulnerability in Atlassian Crowd, published on 31 Jan 2018. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-16858 in the wild and no public exploit code.

Affected product: Atlassian Crowd. 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-2017-16858/ (Markdown: https://insights.sbomify.com/CVE-2017-16858/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-16858
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-16858
- OSV: https://osv.dev/vulnerability/CVE-2017-16858

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-16858/
Summaries are generated and may contain mistakes; the official description above is the record.