Vulnerability in E2bn E2guardian

CVE-2021-44273

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.

Vulnerability class: Improper Certificate Validation

EPSS: 0.010 (58.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-44273?
CVE-2021-44273 is a high-severity vulnerability in E2bn E2guardian, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2021-12-23.
How severe is CVE-2021-44273?
High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2021-44273 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.