cbcvebase.
CVE-2017-6740
published 2017-07-17

CVE-2017-6740: The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow an authenticated…

PriorityP183high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2022-03-24
Exploited in the wild
EPSS
10.79%
95.4th percentile
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.

Affected

77 ranges· showing 25
VendorProductVersion rangeFixed in
ciscoios
ciscoios
ciscoios
ciscoios
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ciscoios
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ciscoios
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Detection & IOCsextracted from sources · hover to see the quote

  • Exploit traffic targets SNMP subsystem via UDP port 161 (standard SNMP port); monitor for crafted SNMP packets directed to Cisco IOS/IOS XE devices over both IPv4 and IPv6
  • All three SNMP versions (1, 2c, 3) are attack vectors; detection should cover SNMP v1, v2c, and v3 traffic to affected Cisco devices
  • For SNMPv2c/v1 exploitation, attacker must supply a valid read-only community string; alert on SNMP GET/SET requests using known community strings from untrusted sources
  • For SNMPv3 exploitation, attacker must present valid user credentials; monitor for authenticated SNMPv3 sessions originating from unexpected or external sources
  • Devices with SNMP enabled that have NOT explicitly excluded the affected MIBs or OIDs should be treated as vulnerable; audit SNMP MIB/OID access control lists on all Cisco IOS/IOS XE devices
  • Track Cisco Bug IDs CSCsy56638, CSCve54313, and CSCve57697 for patch status correlation and affected software version identification
  • ·Workaround exists: explicitly exclude the affected MIBs or OIDs from SNMP access on Cisco IOS/IOS XE devices to mitigate exploitation without patching
  • ·Vulnerability is a buffer overflow in the SNMP subsystem; successful exploitation can result in arbitrary code execution with full device control OR device reload (crash), making it both an RCE and DoS risk

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv3.08.8HIGHCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.09.0CRITICALAV:N/AC:L/Au:S/C:C/I:C/A:C
vulncheck8.8HIGH
cisa8.8HIGH
vendor_cisco8.8HIGH
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