CVE-2021-21240 : httplib2 is a comprehensive HTTP client library for Python. In httplib2 before v

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.

Published 2021-02-08 20:15:12

Updated 2021-02-12 14:56:40

Source GitHub, Inc.

View at NVD, CVE.org

Vulnerability category: Denial of service

Products affected by CVE-2021-21240

Httplib2 Project » Httplib2 » For Python
Versions before (<) 0.19.0
cpe:2.3:a:httplib2_project:httplib2:*:*:*:*:*:python:*:*
Matching versions

Exploit prediction scoring system (EPSS) score for CVE-2021-21240

EPSS FAQ

3.03%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 86 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-21240

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
5.0	MEDIUM	AV:N/AC:L/Au:N/C:N/I:N/A:P	10.0	2.9	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: None Availability Impact: Partial
7.5	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	3.9	3.6	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: None Availability: High
7.5	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	3.9	3.6	GitHub, Inc.
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: None Availability: High

CWE ids for CVE-2021-21240

CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

Assigned by: security-advisories@github.com (Primary)

References for CVE-2021-21240

https://pypi.org/project/httplib2

httplib2 · PyPI
Product;Third Party Advisory
https://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m

Regular Expression Denial of Service (REDoS) in httplib2 · Advisory · httplib2/httplib2 · GitHub
Exploit;Mitigation;Third Party Advisory
https://github.com/httplib2/httplib2/pull/182

parse auth headers using pyparsing instead of regexp by temoto · Pull Request #182 · httplib2/httplib2 · GitHub
Patch;Third Party Advisory
https://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc

parse auth headers using pyparsing instead of regexp · httplib2/httplib2@bd9ee25 · GitHub
Patch;Third Party Advisory

Jump to

Vulnerability Details : CVE-2021-21240

Products affected by CVE-2021-21240

Exploit prediction scoring system (EPSS) score for CVE-2021-21240

CVSS scores for CVE-2021-21240

CWE ids for CVE-2021-21240

References for CVE-2021-21240