CVERadar
CRITICAL · CVSS 3.1 10CISA KEV · added 2025-06-09Metasploit modulePublic PoCEPSS 98.79% (p100)Threat level 95

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

Erlang · Erlang/OTP · NVD published 2025-04-17 · posted 2025-06-09 · last modified 2026-06-17

What it is

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.

WeaknessCWE-306
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (source: [email protected])
CISA due date2025-06-30 (for US federal agencies under BOD; a good deadline for everyone)
ATT&CK tacticsExecution → Lateral Movement

Exploitation evidence

First exploit evidence seen: 2025-04-16 (earliest date across the sources below).

Exploited in the wild

  • CISA KEV: listed since 2025-06-09. Source

Public exploit code

Metasploit

GitHub proof-of-concept repositories

41 public repositories from 41 accounts, first seen 2025-04-18. Most starred: ProDefense/CVE-2025-32433 (142 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · Rapid7 Metasploit Framework module metadata · nomi-sec/PoC-in-GitHub.

Defend the Chain

The attack chain for CVE-2025-32433 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.

Threat level 95/100
Defender level 1 · 0 XP
Chain links broken: 0/2

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Stealth

Defense Impairment

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Pick a red technique card on the board, then choose the defence that stops it.

Defend against T1059 Command and Scripting Interpreter CTID: primary impact

Attackers have exploited this Erlang OTP vulnerability by using reverse shells to obtain unauthenticated access, allowing them to execute remote code on the system.

How to fix it

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)

Fixed versions

  • erlang erlang\/otp: upgrade to 25.3.2.20 or later
  • erlang erlang\/otp: upgrade to 26.2.5.11 or later (affected from 26.0)
  • erlang erlang\/otp: upgrade to 27.3.3 or later (affected from 27.0)
  • cisco confd basic: upgrade to 7.7.19.1 or later
  • cisco confd basic: upgrade to 8.1.16.2 or later (affected from 8.0.18)
  • cisco confd basic: upgrade to 8.2.11.1 or later (affected from 8.2)
  • cisco confd basic: upgrade to 8.3.8.1 or later (affected from 8.3)
  • cisco confd basic: upgrade to 8.4.4.1 or later (affected from 8.4)
  • cisco network services orchestrator: upgrade to 5.7.19.1 or later
  • cisco network services orchestrator: upgrade to 6.1.16.2 or later (affected from 5.8)
  • cisco network services orchestrator: upgrade to 6.2.11.1 or later (affected from 6.2)
  • cisco network services orchestrator: upgrade to 6.3.8.1 or later (affected from 6.3)
  • cisco network services orchestrator: upgrade to 6.4.1.1 or later (affected from 6.4)
  • cisco network services orchestrator: upgrade to 6.4.4.1 or later (affected from 6.4.2)
  • cisco cloud native broadband network gateway: upgrade to 2025.03.1 or later
  • cisco smart phy: upgrade to 25.2 or later
  • cisco ultra packet core: upgrade to 2025.03 or later
  • cisco staros: upgrade to 2025.03 or later
  • cisco optical site manager: upgrade to 25.2.1 or later
  • cisco ncs 2000 shelf virtualization orchestrator firmware: upgrade to 25.1.1 or later
  • cisco enterprise nfv infrastructure software: upgrade to 4.18 or later
  • cisco ultra cloud core: upgrade to 2025.03.1 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

MITRE ATT&CK mitigations for this chain

  • M1033 Limit Software Installation (for T1059) : Prevent user installation of unrequired command and scripting interpreters.
  • M1045 Code Signing (for T1059) : Where possible, only permit execution of signed scripts.
  • M1042 Disable or Remove Feature or Program (for T1059, T1021.004) : Disable or remove any unnecessary or unused shells or interpreters.
  • M1038 Execution Prevention (for T1059) : Use application control where appropriate. For example, PowerShell Constrained Language mode can be used to restrict access to sensitive or otherwise dangerous language elements such as those used to execute arbitrary Windows APIs or files (e.g., `Add-Type`).
  • M1049 Antivirus/Antimalware (for T1059) : Anti-virus can be used to automatically quarantine suspicious files.
  • M1026 Privileged Account Management (for T1059) : When PowerShell is necessary, consider restricting PowerShell execution policy to administrators. Be aware that there are methods of bypassing the PowerShell execution policy, depending on environment configuration. PowerShell JEA (Just Enough Administration) may also be used to sandbox administration and limit what c
  • M1047 Audit (for T1059) : Inventory systems for unauthorized command and scripting interpreter installations.
  • M1021 Restrict Web-Based Content (for T1059) : Script blocking extensions can help prevent the execution of scripts and HTA files that may commonly be used during the exploitation process. For malicious code served up through ads, adblockers can help prevent that code from executing in the first place.
  • M1040 Behavior Prevention on Endpoint (for T1059) : On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent [Visual Basic](https://attack.mitre.org/techniques/T1059/005) and [JavaScript](https://attack.mitre.org/techniques/T1059/007) scripts from executing potentially malicious downloaded content .
  • M1032 Multi-factor Authentication (for T1021.004) : Require multi-factor authentication for SSH connections wherever possible, such as password protected SSH keys.

Detection Generic guidance

  • Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
  • Lateral Movement: Watch for the compromised host authenticating to other internal systems it does not normally talk to.

Response checklist Generic guidance

  1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
  2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
  3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
  4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Sources