What is CVE-2021-33516?

CVE-2021-33516 is a high-severity vulnerability in GNOME Gupnp. CVSS score: 8.1/10. Published 2021-05-24.

How severe is CVE-2021-33516?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in GNOME Gupnp

CVE-2021-33516

An issue was discovered in GUPnP before 1.0.7 and 1.1.x and 1.2.x before 1.2.5. It allows DNS rebinding. A remote web server can exploit this vulnerability to trick a victim's browser into triggering actions against local UPnP services implemented using this library. Depending on the affected service, this could be used for data exfiltration, data tempering, etc.

Published 2021-05-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.011 (63.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 63.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

GNOME Gupnp

References

gitlab.gnome.org/GNOME/gupnp/-/issues/24 (Issue Tracking, Vendor Advisory)
discourse.gnome.org/t/security-relevant-releases-for-gupnp-issue-cve-2021-33516… (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-33516?: CVE-2021-33516 is a high-severity vulnerability in GNOME Gupnp. CVSS score: 8.1/10. Published 2021-05-24.
How severe is CVE-2021-33516?: High severity. CVSS v3 base score is 8.1 out of 10.