CVE-2025-47914: 
cAdvisor vulnerability analysis and mitigation

CVE-2025-47914 is an out-of-bounds read vulnerability in the golang.org/x/crypto/ssh/agent package that can cause SSH Agent server processes to panic when handling malformed identity requests. The flaw affects all versions of golang.org/x/crypto before 0.45.0. It was published on November 19, 2025, with a patch released the same day. The vulnerability carries a CVSS v3.1 base score of 5.3 (Medium) (GitHub Advisory, pkg.go.dev).

The root cause is classified as CWE-125 (Out-of-bounds Read): SSH Agent servers in the golang.org/x/crypto/ssh/agent package fail to validate the size of incoming messages before processing new identity (key addition) requests. When a malformed message is received — one whose declared or implied length exceeds the actual data — the server attempts to read beyond the buffer boundary, triggering a Go runtime panic and crashing the process. No authentication or special privileges are required; any network-reachable client can send a crafted message. The fix is tracked in Go issue #76364 and implemented in code review CL 721960 (GitHub Advisory, go.dev issue, go.dev CL).

Successful exploitation causes the SSH Agent server process to panic and crash, resulting in a denial-of-service condition. This disrupts remote access and authentication workflows that depend on the SSH agent for key management, potentially blocking automated pipelines, CI/CD systems, and interactive SSH sessions. There is no confidentiality or integrity impact; the vulnerability is limited to availability (GitHub Advisory). Downstream products incorporating golang.org/x/crypto — including IBM Storage Defender, IBM Cloud Pak for Business Automation, IBM Guardium Data Security Center, Portainer, Podman, Buildah, and others — are also affected (IBM Advisory).

No public proof-of-concept exploit code is known to exist, and there is no evidence of in-the-wild exploitation at this time (GitHub Advisory). The vulnerability requires no authentication or user interaction, making it trivially triggerable by any network-accessible attacker against an exposed SSH Agent server. The EPSS score is approximately 0.039% (very low probability of exploitation in the next 30 days). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

1. Reconnaissance: Identify services exposing a Go-based SSH Agent server (e.g., applications using golang.org/x/crypto < 0.45.0 with an SSH agent listener) via network scanning or service enumeration.
2. Craft malformed message: Construct an SSH agent protocol message for the SSH2_AGENTC_ADD_IDENTITY (or similar add-identity) request type with an inconsistent or truncated payload — specifically, a message where the declared field lengths exceed the actual bytes provided.
3. Send the message: Transmit the malformed message to the SSH Agent server's listening socket (typically a Unix domain socket or TCP port, depending on deployment) without any prior authentication.
4. Trigger panic: The server attempts to read beyond the buffer boundary during message parsing, causing a Go runtime panic and crashing the SSH Agent server process, resulting in denial of service (GitHub Advisory, go.dev issue).

• Logs: Unexpected Go runtime panic stack traces in application logs referencing golang.org/x/crypto/ssh/agent or agent.go; log entries showing abrupt process termination without a clean shutdown message.
• Process: SSH Agent server process (or the parent application embedding it) repeatedly crashing and restarting; unexpected process exits with non-zero exit codes.
• Network: Unusual or malformed SSH agent protocol messages arriving at the agent socket from unexpected source IPs; high-frequency connection attempts to the SSH agent listener from a single source.

The primary remediation is to upgrade golang.org/x/crypto to version 0.45.0 or later, which includes the fix for this vulnerability (GitHub Advisory, go.dev CL). Downstream product users should apply vendor-specific patches: IBM has released fixes for affected products including Storage Defender Copy Data Management, Cloud Pak for Business Automation, Business Automation Workflow, Guardium Data Security Center, and others (IBM Advisory). As a workaround where patching is not immediately possible, restrict network access to SSH Agent server sockets to trusted hosts only, and avoid exposing SSH agent listeners to untrusted networks.

The Go security team announced the vulnerability via the golang-announce mailing list, and it was catalogued in the Go vulnerability database as GO-2025-4135 (pkg.go.dev). Docker highlighted the vulnerability in a blog post about how Docker Hardened Images patch CVEs rapidly. The issue received coverage in Golang Weekly (issue 580) and was noted by multiple Linux distribution security teams (openSUSE, SUSE, Amazon Linux) who issued advisories for affected packages such as Podman, Buildah, and Trivy. Community reaction has been measured given the moderate severity and limited impact scope.