CVE-2025-2759

What it actually does

Incorrect permissions on folders created by the product installer allow a local low-privileged process to write arbitrary files into directories that are later executed or loaded by a higher-privileged user context.

Why it matters to the business

Attackers who already have a foothold on a system can obtain full control of the affected user account, enabling theft of data, installation of persistent malware, or lateral movement without requiring additional credentials.

How an attack unfolds

An attacker first obtains the ability to run code as a low-privileged user on the target system. They then replace or add files inside the installer-created directories that have overly permissive ACLs. When a higher-privileged user subsequently runs GStreamer components or the system processes files from those directories, the attacker's code executes with elevated privileges.

How to fix it

Upgrade GStreamer to the commit ca9d85c3b7a12cda2c19e4404410b81a1c8c2e0b or later. Re-run the installer on affected systems after the update and verify that created directories receive restrictive ACLs. Until the update can be applied, restrict write access to the affected directories via operating-system ACL changes.

How to confirm the fix worked

Confirm the installed GStreamer source tree contains commit ca9d85c3b7a12cda2c19e4404410b81a1c8c2e0b. Inspect installer-created directories for correct restrictive permissions. Reproduce the installer in a test environment and verify that no low-privileged user can write to the resulting folders.

Typical attack path

1. Obtain low-privileged code execution on the target host
2. Identify installer-created directories with weak permissions
3. Write malicious executables or libraries into those directories
4. Trigger execution by a higher-privileged user or scheduled process
5. Obtain code execution in the context of the target user

How to detect it

Review file-creation and modification events in installer directories for unexpected writes by low-privileged accounts. Examine process creation logs for executables launched from those directories under higher-privileged contexts. Correlate with user-activity logs showing privilege transitions after GStreamer component execution.

What your security team should do

• Prioritize patching all GStreamer installations to the fixed commit within the next maintenance window
• Audit existing installations for weak folder permissions and apply ACL hardening where the update is delayed
• Add the fixed commit hash to internal package manifests and SBOMs to prevent re-introduction
• Include GStreamer installer directories in routine file-integrity monitoring