dbcve.org
Infinite LoopWeakness · CWE-835

CVE-2025-20312

HIGH · 7.7 CVSS v3.1 Published 2025-09-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
83/100
Remediation priority · High
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when parsing a specific SNMP request. An attacker could exploit this vulnerability by sending a specific SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMPv2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMPv3, the attacker must have valid SNMP user credentials for the affected system.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A vulnerability in the SNMP subsystem of Cisco IOS XE Software due to improper error handling when parsing specific SNMP requests. An authenticated attacker sending a crafted SNMP request can trigger the device to reload unexpectedly, causing denial of service. The vulnerability affects SNMP versions 1, 2c, and 3, requiring either valid SNMP community strings (v1/v2c) or SNMP user credentials (v3).

MitigationRestrict SNMP access to authorized management stations via ACLs, disable SNMPv1/v2c and use SNMPv3 with authentication/encryption, and apply Cisco IOS XE software updates when patches become available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device OS and version
    Use 'show version' or 'show inventory' to confirm the device runs Cisco IOS XE Software and note the exact version number.
    Affected if The device runs Cisco IOS XE Software and the version falls within the affected range.
  2. Verify SNMP is enabled
    Run 'show snmp' or check the running configuration with 'show run | include snmp' to see if SNMP is globally enabled.
    Affected if SNMP is enabled on the device.
  3. Check enabled SNMP versions
    Review the SNMP configuration to determine which of SNMP versions 1, 2c, or 3 are active. Look for 'snmp-server community' commands (v1/v2c) or 'snmp-server user' commands (v3).
    Affected if Any of SNMP versions 1, 2c, or 3 are configured and enabled.
  4. Confirm SNMP credentials exist
    Use 'show snmp community' to list configured community strings for v1/v2c, and 'show snmp user' to list configured SNMPv3 users.
    Affected if At least one valid SNMP community string or SNMPv3 user is configured, making the device vulnerable to an authenticated attacker.
  5. Assess SNMP access control
    Review access control lists (ACLs) applied to SNMP with 'show snmp community' or check the configuration for 'snmp-server community XXXX ro/rw ACL_NAME'.
    Affected if SNMP is accessible from untrusted networks without restrictive ACLs, increasing exposure.

A user is affected if the device runs a vulnerable Cisco IOS XE version with SNMP versions 1, 2c, or 3 enabled and configured with valid credentials accessible to attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Restrict SNMP access to authorized management stations via ACLs, disable SNMPv1/v2c and use SNMPv3 with authentication/encryption, and apply Cisco IOS XE software updates when patches become available.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,800
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,880.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-20312 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-20312 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data