Skip to content
Fencer Intel
medium 5.4

CVE-2019-16216 json

Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files.

published 7y ago modified 4mo ago also EUVD-2019-7028

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits
0
none known

Summary

Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.

Patch / fix

  • zulip zulip_server 2.0.5

Is CVE-2019-16216 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

0.68% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.