Security Resilience

CVE-2017-6737

Memory Safety in Cisco Ios 12.0 – 12.4

CISA KEVActive ExploitationEUVD ExploitedMemory Safety
Published
17 July 2017
Modified
22 April 2026
KEV Added
03 March 2022
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.45 99th percentile
Risk Priority 90 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2017-6737 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Cisco Ios. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A vulnerability in the SNMP implementation allows an authenticated remote attacker to trigger a buffer overflow via a crafted packet, leading to either arbitrary code execution or a device reload. The flaw impacts all SNMP versions (1, 2c, and 3) and is tracked as CWE-119. Exploitation requires knowledge of the read-only community string or valid SNMPv3 credentials, and the attack is limited to traffic sent directly to the affected device.

An attacker who meets the authentication prerequisites can obtain full system control or deny service through a reload. The CVSS 3.1 score of 8.8 reflects network attack vector, low complexity, and high impact on confidentiality, integrity, and availability.

Cisco Security Advisories cisco-sa-20170629-snmp and related vendor notices describe patches and workarounds; the vulnerability also appears in the CISA Known Exploited Vulnerabilities catalog, indicating confirmed in-the-wild exploitation.

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)
KEV Date Added
03 March 2022

Related Threats

CVEs Like This One

CVE-2017-6738Same product: Cisco Iosboth on KEV
CVE-2017-6743Same product: Cisco Iosboth on KEV
CVE-2017-6742Same product: Cisco Iosboth on KEV
CVE-2017-6736Same product: Cisco Iosboth on KEV
CVE-2017-6739Same product: Cisco Iosboth on KEV
CVE-2017-6740Same product: Cisco Iosboth on KEV
CVE-2017-6663Same product: Cisco Iosboth on KEV
CVE-2023-20109Same product: Cisco Iosboth on KEV
CVE-2017-6627Same product: Cisco Iosboth on KEV
CVE-2017-6744Same product: Cisco Iosboth on KEV

Affected Assets

cisco
ios
12.0 — 12.4 · 15.0 — 15.6
cisco
ios xe
2.2.0 — 3.17.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

A.8.25 mandates secure SDLC practices (secure coding guidelines, security requirements, testing including code scans and penetration tests, developer training) that reach buffer management and can stop many buffer overruns from reaching production, but leaves a bounded remainder (e.g. flaws in non-software components, incomplete enforcement of guidelines, or post-deployment changes)

blocks

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

blocks

A.8.27 mandates security-by-design principles (e.g. least privilege, fail securely, distrust external input, hardening) plus design reviews that can catch and stop buffer-boundary errors before they reach code, but this is only one minority slice of CWE-119's broad surface (language-specific flaws, unsafe library use, compiler/runtime mitigations, and post-deployment instances remain outside its direct scope).

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-119, a class-level weakness. Rules are authored against its narrower children: CWE-823.

References