CVE-2025-20352: Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks. This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. Note: This vulnerability affects all versions of SNMP.
Description quoted from the CVE record (assigned by cisco, published 2025-09-24).
Weakness: Stack-based Buffer Overflow
How it can be exploited
Exploitable over the network with low attack complexity needing low privileges and no user interaction. Impact: 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
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2025-09-29
- US federal deadline
- 2025-10-20
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2025-12385, CNNVD-202509-3811, EUVD-2025-31023, GHSA-c924-mch4-p3p3
Exploit Observer links 2 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (2)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://github.com/scadastrangelove/cve-2025-20352
- Code repository: https://github.com/sentinel-aidefense/cve-2025-20352
Research and write-ups (1)
- Research or write-up: https://socprime.com/blog/latest-threats/cve-2025-20352-zero-day-vulnerability
Vulnerability databases and vendor advisories (6)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2025-31023
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-c924-mch4-p3p3
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2025-20352
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20352
- Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202509-3811
- Vulnerability database or vendor advisory: https://www.tenable.com/cve/CVE-2025-20352
23 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.415
likely to be attacked soon - VEDAS
- 0.789
some exploit evidence - On CISA KEV
- Yes, since 2025-09-29
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Cisco IOS | version 12.2(55)SE version 12.2(55)SE3 version 12.2(55)SE2 version 12.2(58)SE version 12.2(55)SE1 version 12.2(58)SE1 version 12.2(55)SE4 version 12.2(58)SE2 and 718 more ranges | Not stated |
| Cisco Cisco IOS XE Software | version 3.5.0E version 3.5.1E version 3.5.2E version 3.5.3E version 3.6.0E version 3.6.1E version 3.6.2aE version 3.6.2E and 341 more ranges | Not stated |
| Cisco Cisco IOS XE Catalyst SD-WAN | version 16.9.1 version 16.9.2 version 16.9.3 version 16.9.4 version 16.10.1 version 16.10.2 version 16.10.3 version 16.10.3a and 13 more ranges | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: cisco ios.
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.
Vendor guidance:
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snmp-x4LPhte
- https://nvd.nist.gov/vuln/detail/CVE-2025-20352
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20352 (government-resource)
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.