# CVE-2021-37843: Auth bypass in n/a

> Remote attackers can bypass authentication and log in to user accounts using only the username in Atlassian SAML SSO apps.

- **Severity:** Critical 9.8 (`CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Aug 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-hghq-x3wh-37g2

## What is CVE-2021-37843?

CVE-2021-37843 is a critical authentication bypass vulnerability in n/a, published on 2 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The resolution SAML SSO apps for Atlassian products allow a remote attacker to login to a user account when only the username is known (i.e., no other authentication is provided). The fixed versions are for Jira: 3.6.6.1, 4.0.12, 5.0.5; for Confluence 3.6.6, 4.0.12, 5.0.5; for Bitbucket 2.5.9, 3.6.6, 4.0.12, 5.0.5; for Bamboo 2.5.9, 3.6.6, 4.0.12, 5.0.5; and for Fisheye 2.5.9.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2021-37843?

It affects 1 product.


Products: Atlassian Saml Single Sign On.

## How do I fix CVE-2021-37843?

No fix has been published for CVE-2021-37843 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-37843 being exploited?

There is no known exploitation of CVE-2021-37843 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-13347](https://insights.sbomify.com/CVE-2019-13347/): Auth bypass in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-37843 and fix it if it is affected.

What it is: CVE-2021-37843 is a critical authentication bypass vulnerability in n/a, published on 2 Aug 2021. 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-2021-37843 in the wild and no public exploit code.

Affected product: n/a. 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-2021-37843/ (Markdown: https://insights.sbomify.com/CVE-2021-37843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-37843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-37843
- OSV: https://osv.dev/vulnerability/CVE-2021-37843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-37843/
Summaries are generated and may contain mistakes; the official description above is the record.