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Security Digest · Vulnerability record · Known exploited

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

Exploited in the wild (CISA KEV). Erlang/OTP is a set of libraries for the Erlang programming language.

CISA KEV · added 2025-06-09 CVSS 10.0 Critical EPSS 98.8% · p99.9 Check exposure

Updated By erroneo.us Security Desk16 references Seen in the digest for Jun 9, 2025

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

  • Yes, if you run Erlang Erlang/OTP. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-06-09, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-06-30; treat that as the outer limit, not the target.
  • EPSS 98.8%, percentile 99.9: FIRST’s model estimates a 98.8% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
  • Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
  • Editorial verdict: Check exposure. Erlang/OTP SSH: Unauthenticated RCE (CVE-2025-32433) — The OTP fix is 18 months old, but the bug hides inside appliances and OT gear that patch slowly; inventory anything exposing an Erlang SSH daemon rather than assuming your servers' OpenSSH covers you.

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.

CISA’s summary

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 to—Cisco, NetApp, and SUSE.

Weakness type: CWE-306.

Product: Erlang Erlang/OTP · Assigned by: GitHub_M · Published: 2025-04-16

Affected and fixed versions

VendorProductAffected versions (per CVE record)
erlangotp>= OTP-27.0-rc1, < OTP-27.3.3, >= OTP-26.0-rc1, < OTP-26.2.5.11, < OTP-25.3.2.20

Severity scores

Scored byCVSSScoreVector
GitHub_M3.110 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
  • Attack vector: network (remotely reachable)
  • Attack complexity: low
  • Privileges required: none (no login)
  • User interaction: none
  • Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

  • CISA KEV: added 2025-06-09; federal due date 2025-06-30. Known ransomware use: Unknown.
  • 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.
  • CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
  • FIRST EPSS (model of 2026-10-21): 98.79% probability of exploitation activity in the next 30 days; percentile 99.9.

Timeline

  • — CVE record published by GitHub_M
  • — erroneo.us brief: Erlang/OTP SSH: Unauthenticated RCE (CVE-2025-32433)
  • — Added to CISA’s Known Exploited Vulnerabilities catalog
  • — CISA remediation deadline for US federal agencies
  • — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

  1. sec.cloudapps.cisco.com sec.cloudapps.cisco.com
  2. Listed in CISA KEV notes (github.com) github.com

Vulnerability records

  1. CVE.org record CVE-2025-32433 cve.org
  2. NVD entry CVE-2025-32433 nvd.nist.gov

Government

  1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

  1. github.com github.com
  2. github.com github.com
  3. github.com github.com
  4. openwall.com openwall.com
  5. openwall.com openwall.com
  6. openwall.com openwall.com
  7. openwall.com openwall.com
  8. openwall.com openwall.com
  9. security.netapp.com security.netapp.com
  10. lists.debian.org lists.debian.org
  11. github.com github.com

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