# CVE-2021-37746: Open redirect in n/a

> Claws Mail and Sylpheed clients fail to sufficiently validate links before accepting clicks, potentially allowing open redirect attacks.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **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:** 30 Jul 2021
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-37746, GHSA-7cx5-4rpx-pcm3, MGASA-2021-0408, UBUNTU-CVE-2021-37746

## What is CVE-2021-37746?

CVE-2021-37746 is a medium-severity vulnerability in Fedoraproject Fedora, published on 30 Jul 2021. 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

textview_uri_security_check in textview.c in Claws Mail before 3.18.0, and Sylpheed through 3.7.0, does not have sufficient link checks before accepting a click.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2021-37746?

It affects 3 products.


Products: Claws-Mail Claws-Mail, Fedoraproject Fedora, Sylpheed Project Sylpheed.

## How do I fix CVE-2021-37746?

Upgrade to a fixed version.

## Is CVE-2021-37746 being exploited?

There is no known exploitation of CVE-2021-37746 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2020-15917](https://insights.sbomify.com/CVE-2020-15917/): Security feature bypass in n/a (critical 9.8)
- [CVE-2020-16094](https://insights.sbomify.com/CVE-2020-16094/): Denial of service in n/a (high 7.5)
- [CVE-2015-8614](https://insights.sbomify.com/CVE-2015-8614/): Memory corruption in n/a (high 7.3)
- [CVE-2015-8708](https://insights.sbomify.com/CVE-2015-8708/): Memory corruption in n/a (high 7.3)
- [CVE-2014-2576](https://insights.sbomify.com/CVE-2014-2576/): Security feature bypass in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-37746 and fix it if it is affected.

What it is: CVE-2021-37746 is a medium-severity vulnerability in Fedoraproject Fedora, published on 30 Jul 2021. 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-2021-37746 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-37746/ (Markdown: https://insights.sbomify.com/CVE-2021-37746/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-37746
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-37746
- OSV: https://osv.dev/vulnerability/CVE-2021-37746

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-37746/
Summaries are generated and may contain mistakes; the official description above is the record.