VYPR
← All advisories
Moderate severityNVD Advisory· Published Jul 12, 2018· Updated Aug 5, 2024

CVE-2018-13796

CVE-2018-13796

Description

GNU Mailman before 2.1.28 has a crafted URL injection vulnerability allowing arbitrary text display on a trusted site's web page.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

GNU Mailman before 2.1.28 has a crafted URL injection vulnerability allowing arbitrary text display on a trusted site's web page.

Vulnerability

An issue in GNU Mailman before version 2.1.28 [1][2] allows a crafted URL to inject arbitrary text into a web page served from a trusted site. The bug resides in the CGI scripts that handle input; a specially crafted URL can cause the application to display arbitrary content (including HTML or JavaScript) without proper sanitization. The affected versions are all releases prior to 2.1.28 [1][4].

Exploitation

An attacker only needs to craft a malicious URL and trick a user into clicking it (no authentication or special network position is required). The URL is processed by Mailman's CGI interface, which reflects the injected text back into the page. No user interaction beyond clicking the link is necessary for the text to be displayed [1].

Impact

Successful exploitation allows an attacker to display arbitrary text on a web page from a trusted domain (the Mailman server). This can be used for cross-site scripting (XSS) attacks if HTML/JavaScript is injected, potentially leading to session hijacking, credential theft, or other client-side attacks [1][3]. The integrity of the page content is compromised.

Mitigation

The fix is included in GNU Mailman version 2.1.28 [1][2]. No workaround is available for earlier versions. Users should upgrade to 2.1.28 or later. Ubuntu addressed this in USN-4348-1 [3] as part of a security update. The CVE is not listed on the CISA Known Exploited Vulnerabilities catalog.

References
  1. Bug #1780874 “Arbitrary text injection vulnerability in Mailman ...” : Bugs : GNU Mailman
  2. NVD - CVE-2018-13796
  3. USN-4348-1: Mailman vulnerabilities | Ubuntu security notices | Ubuntu
  4. CVE-2018-13796 - GitHub Advisory Database

AI Insight generated on May 22, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
mailmanPyPI
< 2.1.282.1.28

Affected products

18

Patches

0

No patches discovered yet.

Vulnerability mechanics

Root cause

"Improper input validation in Mailman CGIs allows arbitrary text injection."

Attack vector

An attacker can craft a URL that, when accessed by a user, causes arbitrary text to be displayed on a web page from a trusted site. This vulnerability is due to improper input validation within the Mailman CGI scripts. The specific mechanism involves manipulating URL parameters to inject unintended content into the rendered page. This could lead to various forms of content manipulation or phishing attacks [ref_id=1].

Affected code

The vulnerability resides within the CGI scripts of GNU Mailman. Specifically, the improper input validation occurs in how these scripts handle crafted URLs. The bug report indicates that the fix involves changes across numerous files, suggesting a widespread issue in how URL parameters are processed by the CGI interface [ref_id=1].

What the fix does

The patch addresses the arbitrary text injection vulnerability by improving input validation within the Mailman CGI scripts. While the specific code changes are extensive, the core fix involves ensuring that user-supplied data within URLs is properly sanitized and does not allow for the injection of arbitrary HTML or text. This prevents the rendering of unintended content on trusted web pages [ref_id=1].

Generated on Jun 2, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

9

News mentions

0

No linked articles in our index yet.