CISA KEV High Memory corruption

CVE-2017-6737 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

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.

Published Jul 17, 2017 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: cisco

High

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Mar 3, 2022

How the score was calculated

Confirmed exploitation (CISA KEV)+35
EPSS 45.2% (30-day exploitation probability)+15
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Mar 3, 2022

EPSS FIRST

45.24%

ahead of 99% of scored CVEs · Oct 14, 2026

Affects

Cisco

Ios

CVSS base

8.8

High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Mar 24, 2022 — passed 1666 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Cisco Ios).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cisco	Ios	version 15.0(2)EX11version 15.0(2)EX13version 15.0(2)EX12version 15.2(1)GCversion 15.2(1)GC1version 15.2(1)GC2version 15.2(2)GCversion 15.2(3)GC and 290 more version 15.2(3)GC1version 15.2(4)GCversion 15.2(4)GC1version 15.2(4)GC2version 15.2(4)GC3version 15.4(1)Tversion 15.4(2)Tversion 15.4(1)T2version 15.4(1)T1version 15.4(1)T3version 15.4(2)T1version 15.4(2)T3version 15.4(2)T2version 15.4(1)T4version 15.4(2)T4version 15.2(2a)E2version 15.2(3a)Eversion 15.2(3)E4version 15.2(2)E5bversion 15.2(6a)Eversion 15.2(6)E0cversion 15.2(7a)E0bversion 15.2(7b)E0bversion 15.1(3)MRA3version 15.1(3)MRA4version 15.1(3)SVB1version 15.1(3)SVB2version 15.4(2)S3version 15.3(3)Mversion 15.3(3)M1version 15.3(3)M2version 15.3(3)M3version 15.3(3)M5version 15.3(3)M4version 15.3(3)M6version 15.3(3)M7version 15.3(3)M8version 15.3(3)M9version 15.3(3)M8aversion 15.2(4)JNversion 15.1(3)SVDversion 15.1(3)SVD1version 15.1(3)SVD2version 15.1(3)SVFversion 15.1(3)SVF1version 15.1(3)SVEversion 15.2(4)JAZ1version 15.4(1)CGversion 15.4(2)CGversion 15.1(3)SVGversion 15.5(1)Tversion 15.5(1)T1version 15.5(2)Tversion 15.5(1)T2version 15.5(1)T3version 15.5(2)T1version 15.5(2)T2version 15.5(2)T3version 15.5(2)T4version 15.5(1)T4version 15.2(4)EA10version 15.5(3)Mversion 15.5(3)M1version 15.5(3)M2version 15.5(3)M3version 15.5(3)M4version 15.5(3)M4aversion 15.5(3)M5version 15.3(3)JAA1version 15.0(2)SQDversion 15.0(2)SQD1version 15.0(2)SQD2version 15.0(2)SQD3version 15.0(2)SQD4version 15.0(2)SQD5version 15.0(2)SQD6version 15.0(2)SQD7version 15.0(2)SQD8version 15.6(2)S0aversion 15.6(1)Tversion 15.6(2)Tversion 15.6(1)T0aversion 15.6(1)T1version 15.6(2)T1version 15.6(1)T2version 15.6(2)T2version 15.6(1)T3version 15.6(3)Mversion 15.6(3)M1version 15.6(3)M0aversion 15.6(3)M1bversion 15.6(3)M2version 15.6(3)M2aversion 15.1(3)SVJ2version 15.3(3)JPC5version 15.3(3)JPR1version 12.1(3)XIversion 12.2(4)Bversion 12.2(15)Bversion 12.2(16)B1version 12.2(4)B7version 12.2(4)B2version 12.2(16)B2version 12.2(4)B6version 12.2(4)B1version 12.2(4)B4version 12.2(4)B3version 12.2(4)B8version 12.2(4)B5version 12.2(16)Bversion 12.2(2)XAversion 12.2(2)XA2version 12.2(2)XA3version 12.2(2)XA4version 12.2(2)XA5version 12.2(2)XA1version 12.2(2)XB11version 12.2(2)XB5version 12.2(2)XB2version 12.2(2)XB1version 12.2(2)XB10version 12.2(2)XB7version 12.2(2)XB3version 12.2(2)XB6version 12.2(2)XB14version 12.2(2)XB12version 12.2(2)XB15version 12.2(2)XB8version 12.2(2)XGversion 12.2(4)XLversion 12.2(4)XL5version 12.2(4)XL2version 12.2(4)XL6version 12.2(4)XL4version 12.2(4)XL1version 12.2(4)XL3version 12.2(4)XMversion 12.2(4)XM3version 12.2(4)XM2version 12.2(4)XM4version 12.2(4)XM1version 12.2(3d)version 12.2(5b)version 12.2(1)XS1aversion 12.2(2)XTversion 12.2(2)XT2version 12.2(2)XT3version 12.2(4)XWversion 12.2(4)YAversion 12.2(4)YA6version 12.2(4)YA3version 12.2(4)YA4version 12.2(4)YA1version 12.2(4)YA11version 12.2(4)YA2version 12.2(4)YA9version 12.2(4)YA8version 12.2(4)YA12version 12.2(4)YA10version 12.2(4)YA7version 12.2(2)YCversion 12.2(2)YC4version 12.2(2)YC1version 12.2(2)YC3version 12.2(2)YC2version 12.2(8)YDversion 12.2(8)YD3version 12.2(8)YD2version 12.2(8)YD1version 12.2(4)YFversion 12.2(4)YHversion 12.2(2)XF2version 12.0(7)XK1version 12.0(7)XKversion 12.2(2)DD2version 12.2(1)XDversion 12.2(1)XD2version 12.2(1)XD4version 12.2(1)XD3version 12.2(1)XD1version 12.2(2)XHversion 12.2(2)XH2version 12.2(2)XIversion 12.2(2)XI1version 12.2(2)XI2version 12.2(2)XJversion 12.2(2)XKversion 12.2(2)XK3version 12.2(2)XK2version 12.2(2)XQversion 12.2(2)XQ1version 12.2(4)BWversion 12.2(4)BW1aversion 12.2(4)BW2version 12.2(4)BW1version 12.2(2)BXversion 12.2(2)BX1version 12.2(15)BZ2version 12.2(2)DX3version 12.2(15)MC1cversion 12.2(15)MC1bversion 12.2(15)MC1aversion 12.2(2)XUversion 12.2(8)YJversion 12.2(8)YJ1version 12.2(11)YTversion 12.2(11)YT1version 12.2(11)YT2version 12.2(8)YNversion 12.2(8)YN1version 12.2(9)YOversion 12.2(9)YO3version 12.2(9)YO2version 12.2(9)YO1version 12.4(15)XY5version 12.4(15)XY1version 12.4(15)XYversion 12.4(15)XY2version 12.4(15)XY3version 12.4(15)XZversion 12.4(15)XZ2version 12.4(15)XZ1version 12.4(15)XL3version 12.4(15)XL1version 12.4(15)XL2version 12.4(15)XL4version 12.4(15)XL5version 12.4(15)XLversion 12.3(8)ZAversion 12.4(15)XM1version 12.4(15)XM2version 12.2(33)STE0version 12.4(10b)JDA1version 12.4(3g)JMBversion 12.4(23c)JYversion 12.4(10b)JDCversion 12.4(10b)JDDversion 15.0(1)M1version 15.0(1)M5version 15.0(1)M4version 15.0(1)M3version 15.0(1)M2version 15.0(1)M6version 15.0(1)Mversion 15.0(1)M7version 15.0(1)M10version 15.0(1)M9version 15.0(1)M8version 15.0(1)XA2version 15.0(1)XA4version 15.0(1)XA1version 15.0(1)XA3version 15.0(1)XAversion 15.0(1)XA5version 15.1(2)Tversion 15.1(1)T4version 15.1(3)T2version 15.1(1)T1version 15.1(2)T0aversion 15.1(3)T3version 15.1(1)T3version 15.1(2)T3version 15.1(2)T4version 15.1(1)T2version 15.1(3)Tversion 15.1(2)T2aversion 15.1(3)T1version 15.1(1)Tversion 15.1(2)T2version 15.1(2)T1version 15.1(2)T5version 15.1(3)T4version 15.1(1)T5version 15.1(1)XBversion 15.0(1)XO1version 15.0(1)XOversion 15.0(2)XOversion 15.3(1)Tversion 15.3(2)Tversion 15.3(1)T1version 15.3(1)T2version 15.3(1)T3version 15.3(1)T4version 15.3(2)T1version 15.3(2)T2version 15.3(2)T3version 15.3(2)T4version 12.4(10b)JDEversion 15.0(1)EYversion 15.0(1)EY1	Vulnerable	CVE Program (cve.org) e CISA ADP
Cisco	Ios	≥ 12.0 and ≤ 12.4≥ 15.0 and ≤ 15.6	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.8	CVSS 3.1	High	2.8	5.9	nvd@nist.gov via NIST National Vulnerability Database
8.8	CVSS 3.0	High	2.8	5.9	psirt@cisco.com via NIST National Vulnerability Database
8.8	CVSS 3.0	High	—	—	GitHub, Inc. via GitHub Security Advisories
8.8	CVSS 3.0	High	—	—	cisco via CVE Program (cve.org) e CISA ADP
9.0	CVSS 2.0	High	8.0	10.0	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Mar 3, 2022

Federal deadline

Mar 24, 2022

passed 1666 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 45.24%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Hunt retroactively in logs from before Mar 3, 2022 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · cisco/ios, cisco/ios xe
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · Published → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record published
Oct 13, 2026
Affected products added · cisco/ios
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
CVSS changed · 8.8
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Published
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2022
Added to CISA KEV catalog
Mar 2, 2022 · CISA
2017
CVE published
Jul 17, 2017 · cisco

Source activity

Repeated readings are counted rather than listed.

3× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

7 on the record

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
Vendor Advisory, NIST National Vulnerability Database
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
Vendor Advisory, CVE Program (cve.org) e CISA ADP
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
www.securitytracker.com/id/1038808
Broken Link, Third Party Advisory, VDB Entry, NIST National Vulnerability Database
www.securityfocus.com/bid/99345
Broken Link, Third Party Advisory, VDB Entry, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2017-6737
GitHub Security Advisories
github.com/advisories/GHSA-f29v-pr27-8f5j
GitHub Security Advisories

Elsewhere on this site

Cisco
every CVE for this vendor

2022-03
what else CISA listed that month

Memory corruption
same class

CWE-119
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-20301 A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as… Aug 5, 2026
High CVE-2026-20273 Improper Input Validation in Cisco Ios Xe Aug 5, 2026
Critical CVE-2026-20272 Injection in Cisco Ios Xe Aug 5, 2026
High CVE-2026-20271 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
High CVE-2026-20269 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
High CVE-2026-20270 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2017-6737 is "Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability", rated High. It affects Ios (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 8.8 describes technical severity. EPSS 45.24% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.