Cisco IOS/IOS XE SNMPv1/SNMPv2c/SNMPv3 memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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8.7$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Cisco IOS and IOS XE. The affected element is an unknown function of the component SNMPv1/SNMPv2c/SNMPv3. This manipulation causes memory corruption. This vulnerability is registered as CVE-2017-6736. Remote exploitation of the attack is possible. Furthermore, an exploit is available. You should change the configuration settings.

Detailsinfo

A vulnerability has been found in Cisco IOS and IOS XE (Router Operating System) (version now known) and classified as critical. Affected by this vulnerability is some unknown processing of the component SNMPv1/SNMPv2c/SNMPv3. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability.

The bug was discovered 06/29/2017. The weakness was published 06/29/2017 with Cisco as cisco-sa-20170629-snmp as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. This vulnerability is known as CVE-2017-6736 since 03/09/2017. The attack can be launched remotely. Required for exploitation is a single authentication. Technical details are unknown but a public exploit is available. The advisory points out:

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.

A public exploit has been developed by Artem Kondratenko in Python and been published 7 months after the advisory. It is possible to download the exploit at exploit-db.com. It is declared as attacked. We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 101268 (Cisco IOS SNMP Packet Handling Remote Buffer Overflow Multiple RCE (cisco-sa-20170629-snmp)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CISCO and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316125 (Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerabilities (cisco-sa-20170629-snmp)). The code used by the exploit is:

s0 = bin2oid(sh_dword)  # shellcode dword
s1 = bin2oid('\x00\x00\x00\x00') 
s2 = bin2oid('\xBF\xC5\xB7\xDC')
s3 = bin2oid('\x00\x00\x00\x00')
s4 = bin2oid('\x00\x00\x00\x00')
s5 = bin2oid('\x00\x00\x00\x00')
s6 = bin2oid('\x00\x00\x00\x00')
ra = bin2oid('\xbf\xc2\x2f\x60') # return control flow jumping over 1 stack frame
s0_2 = bin2oid(shift(shellcode_start, k * 4))
ra_2 = bin2oid('\xbf\xc7\x08\x60')
s0_3 = bin2oid('\x00\x00\x00\x00')
ra_3 = bin2oid('\xBF\xC3\x86\xA0')
 
payload = alps_oid.format(s0, s1, s2, s3, s4, s5, s6, ra, s0_2, ra_2, s0_3, ra_3)
The advisory illustrates:
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 CISA Known Exploited Vulnerabilities Catalog lists this issue since 03/03/2022 with a due date of 03/24/2022:
Apply updates per vendor instructions.

It is possible to mitigate the problem by applying the configuration setting . A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

Administrators are advised to allow only trusted users to have SNMP access on an affected system.

The vulnerability is also documented in the databases at Exploit-DB (43450), Tenable (101268), SecurityFocus (BID 99345†) and SecurityTracker (ID 1038808†). Similar entries are available at VDB-102956, VDB-102957, VDB-102958 and VDB-102959. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Cisco): 8.8
Vendor Vector (Cisco): 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CNA Base Score: 8.8
CNA Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Attacked
Author: Artem Kondratenko
Programming Language: 🔍
Download: 🔍

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KEV Added: 🔍
KEV Due: 🔍
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KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 101268
Nessus Name: Cisco IOS SNMP Packet Handling Remote Buffer Overflow Multiple RCE (cisco-sa-20170629-snmp)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 103403
OpenVAS Name: SNMP Remote Code Execution Vulnerabilities in Cisco IOS Software
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Config
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
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Exploit Delay Time: 🔍

Timelineinfo

03/09/2017 🔍
06/29/2017 +112 days 🔍
06/29/2017 +0 days 🔍
06/29/2017 +0 days 🔍
06/29/2017 +0 days 🔍
06/29/2017 +0 days 🔍
06/30/2017 +1 days 🔍
07/07/2017 +7 days 🔍
07/17/2017 +10 days 🔍
01/05/2018 +172 days 🔍
01/05/2018 +0 days 🔍
07/31/2025 +2764 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-20170629-snmp
Researcher: Cisco.
Organization: Cisco
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-6736 (🔍)
GCVE (CVE): GCVE-0-2017-6736
GCVE (VulDB): GCVE-100-102955

OVAL: 🔍

SecurityFocus: 99345 - Cisco IOS and IOS XE Software Multiple Remote Code Execution Vulnerabilities
SecurityTracker: 1038808

scip Labs: https://www.scip.ch/en/?labs.20150108
See also: 🔍

Entryinfo

Created: 06/30/2017 12:57
Updated: 07/31/2025 19:27
Changes: 06/30/2017 12:57 (107), 12/20/2019 09:47 (3), 12/30/2020 10:48 (2), 12/30/2020 10:53 (1), 04/23/2024 13:50 (28), 07/24/2024 16:40 (1), 09/09/2024 22:29 (1), 07/31/2025 19:27 (9)
Complete: 🔍
Cache ID: 216::103

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