Actively exploited · Published Jul 17, 2017 · Assigned by cisco
CVE-2017-6736
High 8.8 Exploited
In plain English
A high-severity memory corruption in IOS from Cisco. Attackers are actively exploiting it in the wild (listed by CISA on March 3, 2022). The chance it is exploited in the next 30 days is estimated at 70.4% (higher than 99.4% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Apply updates per vendor instructions.
CISA guidance
Apply updates per vendor instructions.
Federal agencies must remediate by Mar 24, 2022.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | IOS | 12.1(3a)XI912.1(3)XI12.1(3a)XI812.1(3a)XI312.1(3a)XI112.1(3a)XI712.1(3a)XI612.1(3a)XI4 |
| IntelliShield | Universal Product | N/A |
Weakness: CWE-119 · Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- cisco-sa-20170629-snmp
- 99345 vdb-entry, x_refsource_BID, x_transferred
- 43450 exploit, x_refsource_EXPLOIT-DB, x_transferred
- https://github.com/artkond/cisco-snmp-rce x_refsource_MISC, x_transferred
- 1038808 vdb-entry, x_refsource_SECTRACK, x_transferred
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp x_refsource_CONFIRM, x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6736 government-resource