CVE-2021-44273

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-12-23 · updated 2026-06-17
Weakness: CWE-295

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.

Affected products

E2Bn E2Guardian: from 5.4.0 through 5.4.3r

References

http://www.openwall.com/lists/oss-security/2021/12/23/2
https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2
https://github.com/e2guardian/e2guardian/issues/707
https://lists.debian.org/debian-lts-announce/2023/09/msg00010.html
http://www.openwall.com/lists/oss-security/2021/12/23/2
https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2
https://github.com/e2guardian/e2guardian/issues/707
https://lists.debian.org/debian-lts-announce/2023/09/msg00010.html

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