Vulnerability in Zulip Server
CVE-2019-16215
The Markdown parser in Zulip server before 2.0.5 used a regular expression vulnerable to exponential backtracking. A user who is logged into the server could send a crafted message causing the server to spend an effectively arbitrary amount of CPU time and stall the processing of future messages.
Vulnerability class: ReDoS (Regular Expression 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:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.012 (69.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/ (Vendor Advisory)
- github.com/zulip/zulip/commit/5797f013b3be450c146a4141514bda525f2f1b51 (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-16215?
- CVE-2019-16215 is a medium-severity vulnerability in Zulip Server, classified under Inefficient Regular Expression Complexity. CVSS score: 6.5/10. Published 2019-09-18.
- How severe is CVE-2019-16215?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2019-16215 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.