{"cve":"CVE-2011-1521","nvd":{"published":"2011-05-24T23:55:02.840","modified":"2026-06-16T23:29:32.600","status":"Modified","description":"The urllib and urllib2 modules in Python 2.x before 2.7.2 and 3.x before 3.2.1 process Location headers that specify redirection to file: URLs, which makes it easier for remote attackers to obtain sensitive information or cause a denial of service (resource consumption) via a crafted URL, as demonstrated by the file:///etc/passwd and file:///dev/zero URLs.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-399"],"references":["http://bugs.python.org/issue11662","http://hg.python.org/cpython/file/96a6c128822b/Misc/NEWS","http://hg.python.org/cpython/file/b2934d98dac1/Misc/NEWS","http://hg.python.org/cpython/rev/96a6c128822b/","http://hg.python.org/cpython/rev/b2934d98dac1/"],"products":["python:python"],"source":"nvd","synced_at":"2026-10-19T19:58:50.521460154+00:00"},"epss":{"cve":"CVE-2011-1521","score":0.03564,"percentile":0.89346,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}