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)
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: 0.054 (92.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.050 · newest: 0.054 · change: +0.004
Affected products
- Calibre-Ebook Calibre
- Fedoraproject Fedora — versions 34
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugs.launchpad.net/calibre/+bug/1951979 (Exploit, Issue Tracking, Vendor Advisory)
- github.com/dwisiswant0/advisory/issues/18 (Exploit, Patch, Third Party Advisory, Issue Tracking)
- github.com/kovidgoyal/calibre/compare/v5.31.1...v5.32.0 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (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.