Resource exhaustion in Python
CVE-2020-8492
Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.066 (93.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 93.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.066 · newest: 0.066 · change: 0.000
Affected products
- Python
- Canonical Ubuntu Linux — versions 12.04, 14.04, 16.04
- Debian Linux — versions 9.0
- Fedoraproject Fedora — versions 31, 32
- openSUSE Leap — versions 15.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugs.python.org/issue39503 (Issue Tracking, Vendor Advisory)
- python-security.readthedocs.io/vuln/urllib-basic-auth-regex.html (Exploit, Third Party Advisory)
- github.com/python/cpython/pull/18284 (Patch, Third Party Advisory)
- security.netapp.com/advisory/ntap-20200221-0001/ (Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-03/msg00003.html (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4333-1/ (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4333-2/ (vendor-advisory, Third Party Advisory)
- security.gentoo.org/glsa/202005-09 (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2020-8492?
- CVE-2020-8492 is a medium-severity vulnerability in Python, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2020-01-30.
- How severe is CVE-2020-8492?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2020-8492 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.