Security readout for executives and security teams
Plain-English summary
This flaw affects Cisco IOS and IOS XE devices with SNMP enabled. An attacker who has the required SNMP community string or SNMPv3 credentials could crash the device or take full control. Because CISA lists this CVE in KEV, treat exposed network infrastructure as urgent to verify and remediate.
Executive priority
Prioritize remediation for internet-facing or broadly reachable network devices first. This is not a routine endpoint bug; successful exploitation can disrupt routing and switching or give an attacker control of infrastructure.
Technical view
CVE-2017-6740 is a buffer overflow in the SNMP subsystem of Cisco IOS and IOS XE. Crafted SNMP packets over IPv4 or IPv6 can trigger code execution or reload when directed at an affected device. SNMP v1, v2c, and v3 are affected; exploitation requires the relevant community string or SNMPv3 credentials.
Likely exposure
Exposure is likely on Cisco IOS or IOS XE devices with SNMP enabled that have not excluded the affected MIBs or OIDs. Devices reachable by untrusted networks or using widely known SNMP credentials carry higher operational risk.
Exploitation context
CISA KEV status supports known exploitation. The provided sources do not include exploit details, campaign attribution, or current exploitation volume. The vulnerability is still important because successful exploitation can affect routers, switches, and other network infrastructure directly.
Researcher notes
The evidence supports Cisco IOS and IOS XE SNMP buffer overflow exposure, authenticated network attack requirements, and KEV status. The source bundle does not provide proof-of-concept details, specific exploited versions beyond the affected list, or telemetry on exploitation prevalence.
Mitigation direction
- Inventory Cisco IOS and IOS XE devices with SNMP enabled.
- Apply Cisco's documented workaround for affected MIBs or OIDs.
- Use Cisco IOS Software Checker to identify fixed software.
- Upgrade affected devices to Cisco-recommended fixed releases.
- Review SNMP community strings and SNMPv3 credentials for exposure.
Validation and detection
- Confirm whether SNMP is enabled on each Cisco IOS or IOS XE device.
- Verify device software versions against Cisco advisory guidance.
- Check whether affected MIBs or OIDs are explicitly excluded.
- Confirm SNMP management access is limited to expected sources.
- Review logs for unexpected SNMP activity targeting infrastructure devices.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-119: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2017-6740 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- cisco-sa-20170629-snmpCVE reference
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmpCVE reference · x_refsource_CONFIRM, x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6740CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
