What’s Vulnerable › Vulnerabilities

CVE-2024-28235: Contao possible cookie sharing with external domains while checking protected pages for broken links

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-04-09 · updated 2026-06-17
• Weakness: CWE-200

Description

Contao is an open source content management system. Starting in version 4.9.0 and prior to versions 4.13.40 and 5.3.4, when checking for broken links on protected pages, Contao sends the cookie header to external urls as well, the passed options for the http client are used for all requests. Contao versions 4.13.40 and 5.3.4 have a patch for this issue. As a workaround, disable crawling protected pages.

Affected products

• contao: from 4.9.0 before 4.13.40; from 5.0.0 before 5.3.4 — fixed in 4.13.40, 5.3.4

How to fix

Upgrade to a fixed version: contao 4.13.40, 5.3.4. Check the vendor advisory for mitigations.

References

• https://contao.org/en/security-advisories/session-cookie-disclosure-in-the-crawler
• https://github.com/contao/contao/blob/14e9ef4bc8b82936ba2d0e04164581145a075e2a/core-bundle/src/Resources/contao/classes/Crawl.php#L129
• https://github.com/contao/contao/commit/73a2770e2d3535ec9f1b03d54be00e56ebb8ff16
• https://github.com/contao/contao/commit/79b7620d01ce8f46ce2b331455e0d95e5208de3d
• https://github.com/contao/contao/security/advisories/GHSA-9jh5-qf84-x6pr
• https://contao.org/en/security-advisories/session-cookie-disclosure-in-the-crawler
• https://github.com/contao/contao/blob/14e9ef4bc8b82936ba2d0e04164581145a075e2a/core-bundle/src/Resources/contao/classes/Crawl.php#L129
• https://github.com/contao/contao/commit/73a2770e2d3535ec9f1b03d54be00e56ebb8ff16
• https://github.com/contao/contao/commit/79b7620d01ce8f46ce2b331455e0d95e5208de3d
• https://github.com/contao/contao/security/advisories/GHSA-9jh5-qf84-x6pr

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