Patchfirst
CVE-2017-6742 KEVPublic exploit High · 8.8 EPSS 21.4%

Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

Cisco · IOS and IOS XE Software

Summary

A buffer overflow in the SNMP implementation of Cisco IOS and IOS XE Software allows the flaw to be triggered on affected devices. An authenticated remote attacker who knows the SNMP read-only community string (SNMPv2c or earlier) or valid SNMPv3 user credentials can send a crafted SNMP packet to the device to reload it or execute arbitrary code.

Official description · NVD

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.

Breakdown
68.7 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
4/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

  3. What can follow

First seen exploited 6 years after disclosure. Public exploit code (PoC-in-GitHub) appeared 9 years after disclosure.

  1. Disclosedday 0
  2. First seen exploitedVulnCheck KEV evidence+6 yrs
  3. Added to CISA KEVEU database agrees+6 yrs
  4. Public exploit codePoC-in-GitHub+9 yrs

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

4 , grouped by in kill-chain order 4

ExecutionTA0002

Command and Scripting Interpreter T1059 Medium
MITRE CTID mapping of the KEV entry · primary impact

CVE-2017-6742 is a Simple Network Management Protocol (SNMP) vulnerability in Cisco products related to a buffer overflow condition in the SNMP subsystem. Reported by the NCSC, threat actors exploited CVE-2017-6742 to perform reconnaissance, enumerate router interfaces and deploy custom malware known as "Jaguar Tooth", as detailed in the NCSC’s Jaguar Tooth malware analysis report. This malware obtains further device information which is then exfiltrated over trivial file transfer protocol (TFTP) and enables unauthenticated access via a backdoor.

Hijack Execution Flow T1574 Medium also Stealth
MITRE CTID mapping of the KEV entry · how it is exploited

PersistenceTA0003

TFTP Boot T1542.005 Medium also Stealth
MITRE CTID mapping of the KEV entry · follow-on activity

ExfiltrationTA0010

Exfiltration Over Alternative Protocol T1048 Medium
MITRE CTID mapping of the KEV entry · follow-on activity

Detection

0 rules for this CVE · 115 general rules for its techniques

Rules for this CVE

0 that reference CVE-2017-6742 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

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What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

5 links, grouped by NVD tag
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