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.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2021-44273)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2021-44273)

The remote Debian 10 host has a package installed that is affected by a vulnerability as referenced in the dla-3564 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-3564-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                           Chris Lamb     September 12, 2023                            https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : e2guardian     Version        : 5.3.1-1+deb10u1     CVE ID         : CVE-2021-44273     Debian Bug     : 1003125

    It was discovered that there was a potential Man In the Middle (MITM)     vulnerability in e2guardian, a web content filtering engine.

    Validation of SSL certificates was missing in e2guardian's own MITM     prevention engine. In standalone mode (ie. acting as a proxy or a     transparent proxy) with SSL MITM enabled, e2guardian did not validate     hostnames in certificates of the web servers that it connected to,     and thus was itself vulnerable to MITM attacks.

    For Debian 10 buster, this problem has been fixed in version     5.3.1-1+deb10u1.

    We recommend that you upgrade your e2guardian packages.

    For the detailed security status of e2guardian please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/e2guardian

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
258813	Linux Distros Unpatched Vulnerability : CVE-2021-44273	Nessus	Misc.	high
404213	Alpine: multiple e2guardian packages: security update to 5.4.5r-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
404213	Alpine: multiple e2guardian packages: security update to 5.4.5r-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
181320	Debian dla-3564 : e2guardian - security update	Nessus	Debian Local Security Checks	high

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