Listen to this Post
How the CVE Works (CVE-2025-47914)
The vulnerability exists within the SSH Agent’s process for handling new key identity requests. The agent server fails to perform proper bounds checking on the size of incoming messages before processing them. Specifically, when a `SSH_AGENTC_ADD_IDENTITY` or similar request is received, the code does not validate that the message length field matches the actual amount of data provided. This allows a malicious client to send a crafted, malformed message that is shorter than the expected structure. When the agent attempts to parse this truncated message, it reads memory beyond the bounds of the allocated buffer. This out-of-bounds read accesses invalid or unexpected memory locations, leading to a program state violation. Consequently, the agent process triggers a fatal runtime panic or crash, resulting in a denial of service. The flaw is rooted in the message handling routine where length fields from the network are trusted without verification against the total received packet size. Exploitation does not require authentication, as the agent listens on a local socket accessible to user-space programs. A successful attack terminates the agent, breaking all active SSH connections relying on it and preventing new agent-forwarded authentications.
dailycve form
Platform: SSH Agent
Version: Multiple versions
Vulnerability: Out-of-bounds read
Severity: Critical
date: 2025-11-19
Prediction: 2025-12-18
What Undercode Say:
Analytics
Check if ssh-agent is running ps aux | grep ssh-agent Monitor for agent crashes in system logs journalctl -u ssh --since "1 hour ago" | grep -i panic List authorized keys and agent sockets ls -la ~/.ssh/ echo $SSH_AUTH_SOCK
How Exploit:
A local attacker crafts a malicious, short binary packet posing as an `SSH_AGENTC_ADD_IDENTITY` request and sends it to the SSH Agent’s UNIX socket ($SSH_AUTH_SOCK). The agent trusts the packet’s declared length, reads beyond the buffer, and panics.
Protection from this CVE
Apply official patch. Validate message sizes. Use minimal privileges.
Impact
Denial of Service. Broken SSH connections. Disrupted agent forwarding.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
