# CVE-2021-44273: e2guardian: e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine

CVE-2021-44273 is fixed in e2guardian on 1 platform, first by DEBIAN-CVE-2021-44273, released December 23, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-44273
- Priority: High
- CVSS: 7.4 (high)
- EPSS: 0.0100
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 23, 2021

## Description

e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | e2guardian Debian 12.15 (bookworm) | 5.3.5-3 | [DEBIAN-CVE-2021-44273](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44273.md) | Dec 23, 2021 |
| Linux | e2guardian Debian 13.5 (trixie) | 5.3.5-3 | [DEBIAN-CVE-2021-44273](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44273.md) | Dec 23, 2021 |
| Linux | e2guardian Debian 14 | 5.3.5-3 | [DEBIAN-CVE-2021-44273](https://patchblox.com/security/data/fix/linux/debian-cve-2021-44273.md) | Dec 23, 2021 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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