Critical Vulnerability in Erlang/OTP SSH Implementation: CVE-2025-32433
A critical security vulnerability, CVE-2025-32433, has been identified in the Erlang/Open Telecom Platform (OTP) SSH implementation. This flaw allows attackers to execute arbitrary code without authentication under specific conditions, earning it a maximum CVSS score of 10.0. The vulnerability arises from improper handling of SSH protocol messages, enabling attackers to send connection protocol messages before authentication. If exploited, this could lead to arbitrary code execution within the SSH daemon's context, potentially granting full control over the device if the daemon runs as root.
The vulnerability poses significant risks, particularly to high-availability systems where Erlang is commonly installed due to its robust processing capabilities. Notably, many Cisco and Ericsson devices utilize Erlang, making them susceptible to exploitation. The vulnerability's impact extends to Operational Technology (OT) and Internet of Things (IoT) devices, as well as edge computing systems that rely on Erlang/OTP's SSH library for remote access. Researchers have demonstrated a proof-of-concept exploit, underscoring the urgency for users to apply patches or implement temporary workarounds.
The widespread deployment of Erlang/OTP across critical infrastructure environments heightens the potential consequences of this vulnerability. Unauthorized access to sensitive industrial systems and disruption of critical infrastructure operations are among the severe risks highlighted by security experts. Organizations are urged to upgrade to fixed versions of Erlang/OTP or restrict SSH port access to authorized users as an interim measure.
Threats and Vulnerabilities
CVE-2025-32433 is a critical vulnerability in the Erlang/OTP SSH implementation that allows attackers with network access to execute arbitrary code without authentication. The flaw stems from improper handling of SSH protocol messages, permitting attackers to bypass authentication by sending channel operation messages prematurely. This vulnerability is particularly dangerous if the SSH daemon runs as root, as it could lead to full device control and unauthorized data access or manipulation.
The vulnerability affects all users running an SSH server based on the Erlang/OTP SSH library. It is prevalent in high-availability systems due to Erlang's robust processing support, with many Cisco and Ericsson devices at risk. The vulnerability's impact is exacerbated by its presence in OT and IoT devices, where remote access is facilitated by Erlang/OTP's SSH library. A proof-of-concept exploit has been developed, highlighting the ease with which this vulnerability can be exploited.
Client Impact
Clients using systems with Erlang/OTP SSH implementations are at risk of operational disruptions, data breaches, and financial losses due to CVE-2025-32433. The vulnerability could lead to unauthorized access and control over critical systems, resulting in potential data theft or manipulation. Organizations relying on OT and IoT devices may face significant operational challenges if their infrastructure is compromised.
From a compliance perspective, exploitation of this vulnerability could lead to regulatory challenges and audits, particularly for industries with stringent data protection requirements. Failure to address the vulnerability promptly may result in penalties or reputational damage due to non-compliance with security standards.
Mitigations
To mitigate the risks associated with CVE-2025-32433, clients should consider the following actions
- Upgrade affected systems to the fixed versions of Erlang/OTP: OTP-27.3.3, OTP-26.2.5.11, or OTP-25.3.2.20.
- Implement firewall rules to restrict access to vulnerable SSH servers, allowing only authorized users.
- Regularly monitor network traffic for unusual activity that may indicate exploitation attempts.
- Conduct security assessments of systems using Erlang/OTP to identify potential vulnerabilities.
- Educate staff on recognizing signs of compromise and reporting suspicious activities promptly.
By taking these steps, organizations can reduce their exposure to this critical vulnerability and enhance their overall security posture. It is crucial for clients to act swiftly in applying patches or implementing temporary measures while planning for long-term security improvements.
1898 & Co. Response
1898 & Co. is actively addressing the threat landscape posed by CVE-2025-32433 through a range of services and solutions designed to enhance client security. We are offering tailored vulnerability assessments and patch management services to help clients identify and remediate affected systems promptly. Our team is also providing guidance on implementing effective firewall rules and monitoring strategies to detect potential exploitation attempts.
In collaboration with industry partners and government agencies, 1898 & Co is engaged in ongoing research and threat intelligence gathering activities to stay ahead of emerging threats. We are committed to sharing insights and best practices with our clients to support their security efforts.
Our proactive approach includes case studies demonstrating successful mitigations of similar vulnerabilities, providing clients with real-world examples of effective security measures. By leveraging our expertise and resources, 1898 & Co aims to support clients in navigating the current threat landscape with confidence.