CVE-2021-33516

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-05-24 · updated 2026-06-17

Description

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.

Affected products

GNOME Gupnp: before 1.0.7; from 1.1.0 before 1.2.5 — fixed in 1.0.7, 1.2.5

How to fix

Upgrade to a fixed version: GNOME Gupnp 1.0.7, 1.2.5. Check the vendor advisory for mitigations.

References

https://discourse.gnome.org/t/security-relevant-releases-for-gupnp-issue-cve-2021-33516/6536
https://gitlab.gnome.org/GNOME/gupnp/-/issues/24
https://discourse.gnome.org/t/security-relevant-releases-for-gupnp-issue-cve-2021-33516/6536
https://gitlab.gnome.org/GNOME/gupnp/-/issues/24

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