Cyber Resilience

CVE-2017-6627

Cisco Ios Xe 3.14.0s … 3.18.3vs

CISA KEVActive ExploitationEUVD Exploited
Published
07 September 2017
Modified
22 April 2026
KEV Added
03 March 2022
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.060 93th percentile
Risk Priority 84 floored blend · peak EPSS

Summary

CVE-2017-6627 is a high-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Cisco Ios Xe. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 7% 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 UDP processing code of Cisco IOS versions 15.1, 15.2, and 15.4 as well as IOS XE 3.14 through 3.18 stems from application changes that create UDP sockets and leave them idle without closing them. This flaw, tracked under Cisco Bug IDs CSCup10024, CSCva55744, and CSCva95506, can cause an affected device's input interface queue to retain UDP packets, resulting in a wedge condition and denial of service.

An unauthenticated remote attacker can exploit the issue by sending crafted UDP packets destined for port 0. Successful exploitation holds packets in the input queue until the limit of 250 packets is reached, producing a sustained DoS impact on the affected interface with no requirement for authentication or user interaction. The CVSS 3.1 score of 7.5 reflects the network attack vector and high availability consequences.

The referenced Cisco Security Advisory cisco-sa-20170906-ios-udp provides official guidance on mitigation steps and affected software updates. No information on observed in-the-wild exploitation is included in the supplied details.

EU & UK References

Vulnerability Data

A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing…

more

an interface queue wedge and a denial of service (DoS) condition. The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets. Cisco Bug IDs: CSCup10024, CSCva55744, CSCva95506.

CWE(s)
KEV Date Added
03 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2017-6743Same product: Cisco Iosboth on KEV
CVE-2017-6736Same product: Cisco Iosboth on KEV
CVE-2017-6738Same product: Cisco Iosboth on KEV
CVE-2017-6739Same product: Cisco Iosboth on KEV
CVE-2017-6740Same product: Cisco Iosboth on KEV
CVE-2017-6742Same product: Cisco Iosboth on KEV
CVE-2017-6737Same product: Cisco Iosboth on KEV
CVE-2023-20109Same product: Cisco Iosboth on KEV
CVE-2017-6663Same product: Cisco Iosboth on KEV
CVE-2025-20352Same product: Cisco Iosboth on KEV

Affected Assets

cisco
ios
15.1\(2\)gc, 15.1\(2\)gc1, 15.1\(2\)gc2, 15.1\(4\)gc, 15.1\(4\)gc1
cisco
ios xe
3.14.0s, 3.14.1s, 3.14.2s, 3.14.3s, 3.14.4s

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-404

Contingency plan updates incorporate proper resource shutdown and release steps, preventing attackers from leveraging incomplete cleanup during recovery scenarios.

addresses: CWE-404

Mandates explicit shutdown of the network connection at session conclusion, directly addressing improper resource release.

addresses: CWE-404

Requires proper shutdown/release procedures that include overwriting or isolating data to block unintended transfer via reused system objects.

addresses: CWE-404

Procedures can mandate orderly shutdown or release of resources when failures occur, preventing improper resource handling after a fault.

Mitigating Controls (NIST CSF 2.0) AI

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

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards for correct resource allocation and release.

DE.CM-09 partial match
prevents

Runtime monitoring can detect resource exhaustion caused by improper shutdown or release.

ID.AM-08 partial match
prevents

Lifecycle management of assets can encompass proper resource release at end-of-life or shutdown.

PR.IR-04 partial match
prevents

Capacity management helps surface leaks from unreleased resources but does not prevent the coding flaw.

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.

prevents

Including restart, recovery and media-handling instructions reduces the likelihood that resources or sensitive data will be left in an exposed or improperly released state after a failure.

References