Vulnerability · Published May 16, 2025 · Assigned by redhat
CVE-2025-4476Libsoup: null pointer dereference in libsoup may lead to denial of service
Medium 4.3
In plain English
A medium-severity null pointer dereference in libsoup. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
A denial-of-service vulnerability has been identified in the libsoup HTTP client library. This flaw can be triggered when a libsoup client receives a 401 (Unauthorized) HTTP response containing a specifically crafted domain parameter within the WWW-Authenticate header. Processing this malformed header can lead to a crash of the client application using libsoup. An attacker could exploit this by setting up a malicious HTTP server. If a user's application using the vulnerable libsoup library connects to this malicious server, it could result in a denial-of-service. Successful exploitation requires tricking a user's client application into connecting to the attacker's malicious server.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-4476 |
| Debian:13 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-4476 |
| Debian:12 | libsoup3 | no fix listed | DEBIAN-CVE-2025-4476 |
| Debian:13 | libsoup3 | 3.6.5-2 | DEBIAN-CVE-2025-4476 |
| Ubuntu:22.04:LTS | libsoup2.4 | 2.74.2-3ubuntu0.5 | USN-7543-1 |
| Ubuntu:22.04:LTS | libsoup2.4 | 2.74.2-3ubuntu0.5 | UBUNTU-CVE-2025-4476 |
| Ubuntu:24.04:LTS | libsoup2.4 | 2.74.3-6ubuntu1.5 | USN-7543-1 |
| Ubuntu:24.04:LTS | libsoup2.4 | 2.74.3-6ubuntu1.5 | UBUNTU-CVE-2025-4476 |
| Ubuntu:24.04:LTS | libsoup3 | 3.4.4-5ubuntu0.4 | UBUNTU-CVE-2025-4476 |
| Ubuntu:24.04:LTS | libsoup3 | 3.4.4-5ubuntu0.4 | USN-7543-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| libsoup | 0 – before 3.6.6 | |
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
References
- https://access.redhat.com/security/cve/CVE-2025-4476 vdb-entry, x_refsource_REDHAT
- RHBZ#2366513 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/440
- https://gitlab.gnome.org/GNOME/libsoup/-/work_items/440 exploit