XSS in Zulip Server

CVE-2018-9999

In Zulip Server versions before 1.7.2, there was an XSS issue with user uploads and the (default) LOCAL_UPLOADS_DIR storage backend.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (52.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2018-9999: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: -0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-9999?
CVE-2018-9999 is a medium-severity vulnerability in Zulip Server, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2018-04-18.
How severe is CVE-2018-9999?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2018-9999 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.