What’s Vulnerable › Vulnerabilities

CVE-2024-42353: WebOb's location header normalization during redirect leads to open redirect

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2024-08-14 · updated 2026-06-17
• Weakness: CWE-601

Description

WebOb provides objects for HTTP requests and responses. When WebOb normalizes the HTTP Location header to include the request hostname, it does so by parsing the URL that the user is to be redirected to with Python's urlparse, and joining it to the base URL. `urlparse` however treats a `//` at the start of a string as a URI without a scheme, and then treats the next part as the hostname. `urljoin` will then use that hostname from the second part as the hostname replacing the original one from the request. This vulnerability is patched in WebOb version 1.8.8.

Affected products

• Pylons webob: before 1.8.8 — fixed in 1.8.8

How to fix

Upgrade to a fixed version: Pylons webob 1.8.8. Check the vendor advisory for mitigations.

References

• https://github.com/Pylons/webob/commit/f689bcf4f0a1f64f1735b1d5069aef5be6974b5b
• https://github.com/Pylons/webob/security/advisories/GHSA-mg3v-6m49-jhp3

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