The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could…

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.

Scores

EPSS (exploitation in 30 days)

10.9% · top 4.1% of all CVEs (3 Nov 2026)

CISA SSVC

Exploitation: active · Automatable: no · Technical impact: total

Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.

Weakness

• CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (opens in a new tab)Other CVEs with CWE-119

Affected products

• Cisco · IOS

  • affected 12.2(53)SE1
  • affected 12.2(55)SE
  • affected 12.2(50)SE2
  • affected 12.2(50)SE1
  • affected 12.2(50)SE5
  • affected 12.2(53)SE
  • affected 12.2(55)SE3
  • affected 12.2(55)SE2
  • affected 12.2(52)SE
  • affected 12.2(58)SE
  • affected 12.2(50)SE3
  • affected 12.2(55)SE1
  • affected 12.2(53)SE2
  • affected 12.2(52)SE1
  • affected 12.2(54)SE
  • affected 12.2(50)SE4
  • affected 12.2(50)SE
  • affected 12.2(58)SE1
  • affected 12.2(55)SE4
  • affected 12.2(58)SE2
  • affected 12.2(55)SE5
  • affected 12.2(55)SE6
  • affected 12.2(55)SE7
  • affected 12.2(55)SE8
  • affected 12.2(55)SE9
  • affected 12.2(55)SE10
  • affected 12.2(55)SE11
  • affected 12.2(53)EX
  • affected 12.2(52)EX
  • affected 12.2(55)EX
  • affected 12.2(52)EX1
  • affected 12.2(55)EX1
  • affected 12.2(55)EX2
  • affected 12.2(55)EX3
  • affected 12.2(58)EX
  • affected 12.2(55)EY
  • affected 12.2(52)EY1
  • affected 12.2(52)EY
  • affected 12.2(53)EY
  • affected 12.2(52)EY2
  • and 297 more

• Cisco · Cisco IOS XE Software

  • affected 3.2.0SG
  • affected 3.2.1SG
  • affected 3.2.2SG
  • affected 3.2.3SG
  • affected 3.2.4SG
  • affected 3.2.5SG
  • affected 3.2.6SG
  • affected 3.2.7SG
  • affected 3.2.8SG
  • affected 3.2.9SG
  • affected 3.2.10SG
  • affected 3.2.11SG
  • affected 3.3.0SG
  • affected 3.3.2SG
  • affected 3.3.1SG
  • affected 3.2.0SE
  • affected 3.2.1SE
  • affected 3.2.2SE
  • affected 3.2.3SE
  • affected 3.3.0SE
  • affected 3.3.1SE
  • affected 3.3.2SE
  • affected 3.3.3SE
  • affected 3.3.4SE
  • affected 3.3.5SE
  • affected 3.4.0SG
  • affected 3.4.2SG
  • affected 3.4.1SG
  • affected 3.4.3SG
  • affected 3.4.4SG
  • affected 3.4.5SG
  • affected 3.4.6SG
  • affected 3.4.7SG
  • affected 3.4.8SG
  • affected 3.5.0E
  • affected 3.5.1E
  • affected 3.5.2E
  • affected 3.5.3E
  • affected 3.6.0E
  • affected 3.6.1E
  • and 51 more

What to do

Exploitation: At the time of initial publication, Cisco was aware of external knowledge of the vulnerabilities described in this advisory and, as a precaution, notified customers about the potential for exploitation. On January 6, 2017, a security researcher published functional exploit code for these vulnerabilities. The Cisco Product Security Incident Response Team (PSIRT) is aware of exploitation of the following vulnerabilities that are described in this advisory: CVE-2017-6736 CVE-2017-6737 CVE-2017-6738 CVE-2017-6739 CVE-2017-6740 CVE-2017-6742 CVE-2017-6743 CVE-2017-6744 The Cisco PSIRT is aware of exploit code available for CVE-2017-6741. Additional information can be found at Cisco TALOS: DNS Hijacking Abuses Trust In Core Internet Service ["https://blog.talosintelligence.com/2019/04/seaturtle.html"].

References (5)

• cisco-sa-20170629-snmp (opens in a new tab)
• 99345 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
• 1038808 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp (opens in a new tab)x_refsource_CONFIRMx_transferred
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6738 (opens in a new tab)government-resource

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• CISA KEV catalog (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2017-6738](https://trackcve.app/badge/CVE-2017-6738.svg)](https://trackcve.app/cve/CVE-2017-6738)

Record last updated 21 Oct 2025, 23:55 UTC.