cbcvebase.
CVE-2017-6743
published 2017-07-17

CVE-2017-6743: 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
10.55%
95.3th 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

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

port161/udp (SNMP)
  • Detect crafted SNMP packets (GET/SET requests) targeting Cisco IOS/IOS XE devices; buffer overflow attempts may manifest as malformed or oversized SNMP PDUs directed at the device's management plane.
  • Monitor for exploitation attempts using SNMP v1 or v2c with a known read-only community string, as well as SNMP v3 with valid user credentials — all three SNMP versions are exploitable.
  • Flag any Cisco IOS/IOS XE device that has SNMP enabled and has not explicitly excluded the affected MIBs or OIDs as a high-priority detection target.
  • Track Cisco bug IDs CSCsy56638, CSCve54313, and CSCve57697 when correlating vendor advisories or patch telemetry to confirmed vulnerable/patched device states.
  • ·The workaround is to explicitly exclude the affected MIBs or OIDs from SNMP access; devices that have not done this remain vulnerable regardless of SNMP version in use.
  • ·Exploitation requires authentication: SNMP v1/v2c requires knowledge of the read-only community string; SNMP v3 requires valid user credentials — unauthenticated exploitation is not possible.
  • ·Only traffic directed to the affected system (i.e., unicast to the device's own address) can be used to exploit these vulnerabilities — transit SNMP traffic is not a vector.

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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