Unauth RCE in Erlang/OTP SSH Server <27.3.3
CVE-2025-32433 Published on April 16, 2025
Erlang/OTP SSH Vulnerable to Pre-Authentication RCE
Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20, a SSH server may allow an attacker to perform unauthenticated remote code execution (RCE). By exploiting a flaw in SSH protocol message handling, a malicious actor could gain unauthorized access to affected systems and execute arbitrary commands without valid credentials. This issue is patched in versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20. A temporary workaround involves disabling the SSH server or to prevent access via firewall rules.
Known Exploited Vulnerability
This Erlang Erlang/OTP SSH Server Missing Authentication for Critical Function Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Erlang Erlang/OTP SSH server contains a missing authentication for critical function vulnerability. This could allow an attacker to execute arbitrary commands without valid credentials, potentially leading to unauthenticated remote code execution (RCE). By exploiting a flaw in how SSH protocol messages are handled, a malicious actor could gain unauthorized access to affected systems. This vulnerability could affect various products that implement Erlang/OTP SSH server, including—but not limited .
The following remediation steps are recommended / required by June 30, 2025: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Analysis
CVE-2025-32433 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
Missing Authentication for Critical Function
The software does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Products Associated with CVE-2025-32433
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Affected Versions
erlang otp:- Version >= OTP-27.0-rc1, < OTP-27.3.3 is affected.
- Version >= OTP-26.0-rc1, < OTP-26.2.5.11 is affected.
- Version < OTP-25.3.2.20 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.