# CVE-2021-40849: Auth bypass in n/a

> Attackers can exploit web service tokens to log into accounts, leading to information disclosure and privilege escalation in Mahara.

- **Severity:** Critical 9.8 (`CVSS:3.1/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:** 3 Nov 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r6xp-85fr-87p6

## What is CVE-2021-40849?

CVE-2021-40849 is a critical authentication bypass vulnerability in Mahara Mahara, published on 3 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Mahara before 20.04.5, 20.10.3, 21.04.2, and 21.10.0, the account associated with a web services token is vulnerable to being exploited and logged into, resulting in information disclosure (at a minimum) and often escalation of privileges.

Weakness: CWE-613 (DEPRECATED: Insufficient Session Expiration)

## Which versions are affected by CVE-2021-40849?

It affects 1 product.


Products: Mahara Mahara.

## How do I fix CVE-2021-40849?

No fix has been published for CVE-2021-40849 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40849 being exploited?

There is no known exploitation of CVE-2021-40849 in the wild and no public exploit code.

## Other vulnerabilities in Mahara Mahara

- [CVE-2022-45134](https://insights.sbomify.com/CVE-2022-45134/): Deserialization in n/a (critical 9.8)
- [CVE-2022-44544](https://insights.sbomify.com/CVE-2022-44544/): Command injection in n/a (critical 9.8)
- [CVE-2017-1000152](https://insights.sbomify.com/CVE-2017-1000152/): Auth bypass in n/a (critical 9.8)
- [CVE-2017-1000153](https://insights.sbomify.com/CVE-2017-1000153/): Auth bypass in n/a (critical 9.8)
- [CVE-2017-1000154](https://insights.sbomify.com/CVE-2017-1000154/): Auth bypass in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40849 and fix it if it is affected.

What it is: CVE-2021-40849 is a critical authentication bypass vulnerability in Mahara Mahara, published on 3 Nov 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-2021-40849 in the wild and no public exploit code.

Affected product: Mahara Mahara. 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-2021-40849/ (Markdown: https://insights.sbomify.com/CVE-2021-40849/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40849
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40849
- OSV: https://osv.dev/vulnerability/CVE-2021-40849

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40849/
Summaries are generated and may contain mistakes; the official description above is the record.