Resource exhaustion in Calibre-ebook Calibre
CVE-2021-44686
calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in html_preprocess_rules in ebooks/conversion/preprocess.py.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.050 (91.1th percentile) — read the EPSS interpretation.
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.
Affected products
- Calibre-ebook Calibre
- Fedoraproject Fedora — versions 34
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Exploit, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- cve@mitre.org (Exploit, Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
- cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2021-44686?
- CVE-2021-44686 is a high-severity vulnerability in Calibre-ebook Calibre, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-12-07.
- How severe is CVE-2021-44686?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-44686 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.