CVE-2025-32728 Overview
In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation stating that it disables X11 and agent forwarding.
Critical Impact
Although the vulnerability is categorized as low severity, it can lead to unexpected behavior in environments relying on disabling X11 and agent forwarding.
Affected Products
- OpenBSD OpenSSH
- Debian Debian Linux
Discovery Timeline
- Not Available - Vulnerability discovered by Not Available
- Not Available - Responsible disclosure to openbsd
- Not Available - CVE CVE-2025-32728 assigned
- Not Available - openbsd releases security patch
- 2025-04-10 - CVE CVE-2025-32728 published to NVD
- 2025-05-22 - Last updated in NVD database
Technical Details for CVE-2025-32728
Vulnerability Analysis
The vulnerability involves a misbehavior of the DisableForwarding directive, which does not prevent X11 and agent forwarding as intended. This discrepancy could lead to unintended information flows, posing security risks in sensitive environments.
Root Cause
The root cause is attributed to improper handling and enforcement in the code related to the DisableForwarding settings.
Attack Vector
Local
# This reflects a configuration example
Host *
DisableForwarding yes
Detection Methods for CVE-2025-32728
Indicators of Compromise
- Unusual SSH authentication successes with forwarding enabled
- Logs showing unexpected forwarding usage
- Anomalous network traffic indicative of X11 or agent forwarding
Detection Strategies
Inspect SSH configurations and monitor logs for unauthorized forwarding attempts, particularly where DisableForwarding should enforce stricter controls.
Monitoring Recommendations
Utilize network intrusion detection systems (NIDS) to alert on unusual forwarding patterns. Regularly audit SSH logs for unexpected activity with a focus on Forwarding parameters.
How to Mitigate CVE-2025-32728
Immediate Actions Required
- Review SSH configurations across all systems
- Deploy the latest OpenSSH patches
- Audit network traffic and authentication logs
Patch Information
Patches are available and can be found at the OpenSSH GitHub repository.
Workarounds
Ensure SSH configurations explicitly set forwarding options in accordance with documentation and organizational policies. Consider additional measures such as network-level restrictions on forwarding channels if an environment requires it.
# Consider modifying SSHD configuration with stricter settings
sudo vi /etc/ssh/sshd_config
# Enforce the desired security posture
PermitX11Forwarding no
AllowAgentForwarding no
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
