CVE-2025-32433: Erlang Erlang/OTP SSH Server Missing Authentication for Critical Function Vulnerability

CVE-2025-32433 is a missing-authentication flaw in the SSH server component of Erlang/OTP. An unauthenticated attacker who can reach the service may execute arbitrary commands, resulting in remote code execution. Because Erlang/OTP is embedded in many network and storage products, the exposure can extend well beyond pure Erlang deployments and into infrastructure that security teams may not immediately associate with the language runtime.

The issue matters because SSH is commonly left reachable for management and because successful exploitation requires no credentials. Confirm every detail against the vendor advisory for your specific product before acting.

How it works

The vulnerability is classified as CWE-306: Missing Authentication for Critical Function. In the Erlang/OTP SSH server, certain protocol messages that should be gated behind successful authentication can be processed without valid credentials. An attacker who can send crafted SSH traffic to an affected listener may therefore invoke privileged operations that lead to arbitrary command execution.

No public exploit code or precise message-sequence details are supplied here; treat any such claims as unconfirmed until verified against the official advisory. The practical outcome is unauthenticated remote code execution on systems that expose the vulnerable SSH implementation.

Am I affected? How to find it in your systems

Erlang/OTP SSH appears both as a standalone library and, more commonly, as an embedded component inside appliances and operating-system distributions. CISA notes that products from vendors including Cisco, NetApp and SUSE may be affected, among others that ship Erlang/OTP.

• Inventory every host or appliance that presents an SSH service and that is known (or suspected) to use Erlang/OTP. Check product documentation, package manifests, or vendor support portals for the presence of Erlang/OTP SSH.
• Compare the installed version or build identifier against the fixed releases listed in the vendor advisory for that product. Do not rely on generic Erlang version numbers; the advisory for each vendor is authoritative.
• Review configuration for any non-standard SSH ports or management interfaces that may still expose the service.
• For detection of possible exploitation, examine SSH and system logs for unexpected command execution, new processes spawned by the SSH daemon, or authentication-bypass patterns. Because the flaw bypasses authentication, traditional failed-login counters may not flag the activity; look instead for anomalous post-connection behavior.

If inventory tools cannot identify the component, treat any SSH-exposed Erlang-based product as potentially vulnerable until the vendor confirms otherwise.

How to remediate

Apply the vendor-supplied update that addresses CVE-2025-32433 as the primary remediation. Follow the exact package, firmware or patch instructions published by the product vendor (Cisco, NetApp, SUSE or others). CISA directs organizations to apply those mitigations, to follow BOD 22-01 guidance where cloud services are involved, or to discontinue use of the product if no mitigation is available.

After patching, re-validate that the SSH service is running the corrected code and that any temporary work-arounds have been removed. For the broader class of missing-authentication flaws, also ensure that management interfaces are not unnecessarily exposed and that least-privilege principles are enforced on the accounts that the service ultimately uses.

If you can't patch immediately

• Segment the affected systems so that the SSH port is reachable only from a tightly controlled management network or jump host.
• If a web application firewall or network IPS is in the path, enable any vendor-provided virtual-patch signatures for this CVE; confirm signature coverage with the security-tool vendor.
• Disable the Erlang/OTP SSH server entirely if the product allows it and if alternative management channels exist.
• Increase monitoring and alerting on the SSH listener for anomalous session behavior, unexpected process creation, or outbound connections initiated by the SSH process.
• Document the temporary controls and set a firm deadline for applying the permanent vendor update.

These measures reduce but do not eliminate risk; treat them as short-term bridges only.

If your data may have been exposed

Actively exploited remote-code-execution vulnerabilities frequently lead to full system compromise and subsequent data theft. If logs or other indicators suggest that an unauthenticated session may have succeeded, assume the host is untrusted, isolate it, and begin incident-response procedures. As a quick personal check, you can run a free exposure scan of your email address against known breach data sets to see whether any credentials associated with the environment have already appeared in public dumps.