Overview
CVE-2025-47914 is a medium severity vulnerability affecting SSH Agent servers. The vulnerability stems from a failure to properly validate the size of incoming messages when processing new identity requests. This can lead to an out-of-bounds read if a malformed message is received, potentially causing the program to panic and crash.
Technical Details
The core issue lies within the SSH Agent’s handling of message lengths related to identity requests. Specifically, when a client attempts to add a new identity to the agent, the agent receives a message indicating the size of the identity data. CVE-2025-47914 arises because the agent doesn’t sufficiently validate that the reported size is within reasonable bounds before attempting to read the data. An attacker could craft a malicious message with an excessively large or otherwise invalid size, leading to an attempt to read memory beyond the allocated buffer. This out-of-bounds read can trigger a panic (crash) in the Go-based SSH agent implementations.
CVSS Analysis
This vulnerability has been assigned a CVSS score of 5.3, indicating a MEDIUM severity. The CVSS vector likely includes factors such as:
- Attack Vector (AV): Network (N) – The vulnerability is exploitable over a network.
- Attack Complexity (AC): Low (L) – The conditions for exploitation are easily met.
- Privileges Required (PR): None (N) – No privileges are required to exploit the vulnerability.
- User Interaction (UI): None (N) – No user interaction is required.
- Scope (S): Unchanged (U) – A successful attack only affects the vulnerable component.
- Confidentiality Impact (C): None (N) – There is no impact to confidentiality.
- Integrity Impact (I): None (N) – There is no impact to integrity.
- Availability Impact (A): High (H) – The service is unavailable. The primary impact is a denial of service due to the panic.
While the vulnerability doesn’t lead to data leakage or privilege escalation, the potential for denial of service makes it a concern, particularly in environments where SSH Agent availability is critical.
Possible Impact
The primary impact of CVE-2025-47914 is a denial-of-service (DoS) condition. An attacker could send a crafted message to the SSH Agent server, causing it to panic and terminate. This could disrupt SSH authentication processes and prevent users from accessing systems that rely on the agent for authentication. In highly automated environments, such as CI/CD pipelines that use SSH for deployment, this vulnerability could significantly impact operations.
Mitigation and Patch Steps
The recommended mitigation is to update to a patched version of the affected software. Specifically, examine your Go toolchain and dependencies to ensure you are not using vulnerable versions of related packages. Refer to the official Go security advisories and package documentation for specific upgrade instructions.
Here’s a general approach to mitigating this vulnerability:
- Identify Affected Systems: Determine which systems are running SSH Agent servers that might be vulnerable.
- Apply Patches: Apply the necessary patches or updates provided by the software vendor. The fix likely involves adding validation checks to ensure message sizes are within acceptable limits.
- Monitor and Detect: Implement monitoring and alerting mechanisms to detect unusual activity related to SSH Agent communication, such as frequent crashes or malformed messages.
Check the linked references below for specific patch information and affected versions.
