Resource exhaustion in Httplib2
CVE-2021-21240
httplib2 is a comprehensive HTTP client library for Python. In httplib2 before version 0.19.0, a malicious server which responds with long series of "\xa0" characters in the "www-authenticate" header may cause Denial of Service (CPU burn while parsing header) of the httplib2 client accessing said server. This is fixed in version 0.19.0 which contains a new implementation of auth headers parsing using the pyparsing library.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.036 (89.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.036 · newest: 0.036 · change: 0.000
Affected products
- Httplib2 — versions < 0.19.0
- Httplib2 Project
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m (Exploit, Third Party Advisory, Mitigation)
- github.com/httplib2/httplib2/pull/182 (Patch, Third Party Advisory)
- github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc (Patch, Third Party Advisory)
- pypi.org/project/httplib2 (Product, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-21240?
- CVE-2021-21240 is a high-severity vulnerability in Httplib2, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-02-08.
- How severe is CVE-2021-21240?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-21240 known to be exploited?
- 18 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.