Detections
Analytics

FreeBSD : traefik -- Bypassing security controls via special characters (91b9790e-de65-11f0-b893-5404a68ad561)

medium Nessus Plugin ID 279496

Language:

Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 91b9790e-de65-11f0-b893-5404a68ad561 advisory.

 The traefik project reports:
 There is a potential vulnerability in Traefik managing the requests using a PathPrefix, Path or PathRegex matcher.
 When Traefik is configured to route the requests to a backend using a matcher based on the path; if the request path contains an encoded restricted character from the following set ('/', '', 'Null', ';', '?', '#'), it is possible to target a backend, exposed using another router, by-passing the middlewares chain.

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

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

Solution

Update the affected packages.

See Also

https://nvd.nist.gov/vuln/detail/CVE-2025-66490

http://www.nessus.org/u?900bbbb0

Plugin Details

Severity: Medium

ID: 279496

File Name: freebsd_pkg_91b9790ede6511f0b8935404a68ad561.nasl

Version: 1.1

Type: local

Published: 12/21/2025

Updated: 12/21/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.3

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2025-66490

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 5.5

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Vulnerability Information

CPE: cpe:/o:freebsd:freebsd, p-cpe:/a:freebsd:freebsd:traefik

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/21/2025

Vulnerability Publication Date: 12/8/2025

Reference Information

CVE: CVE-2025-66490

IAVB: 2025-B-0202