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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.010 (60.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 60.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/e2guardian/e2guardian/issues/707 (Exploit, Patch, Third Party Advisory, Issue Tracking)
- github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2 (Patch, Third Party Advisory)
- www.openwall.com/lists/oss-security/2021/12/23/2 (mailing-list, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2023/09/msg00010.html (mailing-list)
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.