CVE-2021-32813
MEDIUMDescription
Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 63% of all known CVEs.
References
Related Vulnerabilities
Other CWE-913 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-68613 | Critical | 9.9 | 98% | KEV | Fix |
| CVE-2023-50386 | High | 8.8 | 84% | - | Fix |
| CVE-2023-43177 | Critical | 9.8 | 82% | - | Fix |
| CVE-2023-29017 | Critical | 10.0 | 63% | - | Fix |
| CVE-2022-36067 | Critical | 10.0 | 48% | - | Fix |
| CVE-2023-6184 | Medium | 5.0 | 47% | - | - |
Common questions
How do I fix CVE-2021-32813?
Upgrade traefik to 2.4.13 or later.
Is CVE-2021-32813 being actively exploited?
Not that we know of. CVE-2021-32813 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.1% is the estimated probability that it will be exploited in the next 30 days. That is higher than 63% of all scored CVEs.
How severe is CVE-2021-32813?
CVE-2021-32813 has a CVSS v3 base score of 4.8, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-32813 affect?
Published advisories record a fix for traefik (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2021-32813
Markdown
[](https://tridentstack.com/cve/CVE-2021-32813)HTML
<a href="https://tridentstack.com/cve/CVE-2021-32813"><img src="https://tridentstack.com/cve/badge/CVE-2021-32813.svg" alt="CVE-2021-32813"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.