CVE-2017-6627
Cisco IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service Vulnerability
Description
CVE-2017-6627 is a denial-of-service vulnerability in Cisco IOS and IOS XE Software. A vulnerability in the UDP processing code of Cisco IOS and IOS XE could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and denial of service. Successful exploitation could result in denial of service through system crashes on affected devices. CISA has added CVE-2017-6627 to the Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. The EPSS score of 10.83% (93.3rd percentile) indicates a high likelihood of exploitation activity.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| cisco | ios | 15.1\(2\)gc; 15.1\(2\)gc1; 15.1\(2\)gc2; 15.1\(4\)gc; 15.1\(4\)gc1; 15.1\(4\)gc2; 15.2\(1\)gc; 15.2\(1\)gc1; 15.2\(1\)gc2; 15.2\(2\)gc; 15.2\(3\)gc; 15.2\(3\)gc1; 15.2\(3r\)gca; 15.2\(4\)gc; 15.2\(4\)gc1; 15.2\(4\)gc2; 15.2\(4\)gc3; 15.4\(1\)t; 15.4\(1\)t1; 15.4\(1\)t2; 15.4\(1\)t3; 15.4\(1\)t4; 15.4\(2\)t; 15.4\(2\)t1; 15.4\(2\)t2; 15.4\(3\)m; 15.4\(3\)m1; 15.4\(3\)m2; 15.4\(3\)m2.2; 15.4\(3\)m3; 15.4\(3\)m4; 15.4\(3\)m5; 15.4\(3\)m6; 15.4\(3\)m6a; 15.4\(3\)m7 |
| cisco | ios xe | 3.14.0s; 3.14.1s; 3.14.2s; 3.14.3s; 3.14.4s; 3.15.0s; 3.15.1cs; 3.15.1s; 3.15.2s; 3.15.3s; 3.15.4s; 3.16.0cs; 3.16.0s; 3.16.1as; 3.16.1s; 3.16.2as; 3.16.2bs; 3.16.2s; 3.16.3as; 3.16.3s; 3.16.4as; 3.16.4bs; 3.16.4ds; 3.16.4s; 3.16.5s; 3.16.6s; 3.17.0s; 3.17.1as; 3.17.1s; 3.17.3s; 3.18.0as; 3.18.0s; 3.18.1s; 3.18.2s; 3.18.3s; 3.18.3vs |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- http://www.securityfocus.com/bid/100644(Broken Link, Third Party Advisory, VDB Entry)
- http://www.securitytracker.com/id/1039289(Broken Link, Third Party Advisory, VDB Entry)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp(Mitigation, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6627(US Government Resource)
Weakness Type
CWE-399: Resource Management Errors
CWE-399 (Resource Management Errors) is a weakness classification that describes the underlying vulnerability mechanism exploited in CVE-2017-6627. In this case, the weakness relates to how Cisco IOS and IOS XE Software handles UDP packet processing, leading to exploitable conditions.
Learn more: CWE-399 — Resource Management Errors
Impact Analysis
CVE-2017-6627 threatens the availability of Cisco IOS and IOS XE Software, as exploitation can cause interface queue exhaustion, resulting in service disruption. With a CVSS score of 7.5 (HIGH) and a network-based attack vector requiring no authentication, the barrier to exploitation is low. In enterprise environments, repeated exploitation could cause sustained network outages affecting business operations, communications, and service availability. Network infrastructure devices are high-value targets, and their unavailability can have cascading effects across the organization.
Exploit Maturity
CVE-2017-6627 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming that this vulnerability has been exploited in real-world attacks. The EPSS score of 10.83% (93.3rd percentile) places it among the most likely vulnerabilities to be exploited. Organizations should treat this vulnerability as an active and ongoing threat requiring immediate remediation.
Remediation
- Apply vendor updates immediately as required by CISA KEV: Apply updates per vendor instructions.
- If immediate patching is not possible, implement interim mitigations such as restricting access to the affected UDP processing services to trusted networks only using access control lists.
- Monitor affected devices for signs of exploitation, including unexpected reloads, unusual network traffic, and anomalous process behavior.
- Ensure network monitoring and alerting is configured to detect denial-of-service conditions affecting the Cisco IOS and IOS XE Software infrastructure.
- Maintain up-to-date device configurations and backups to enable rapid recovery if exploitation causes device reloads.
Technical Details
CVE-2017-6627 is a denial-of-service vulnerability in the UDP processing code of Cisco IOS and IOS XE Software. The vulnerability allows an unauthenticated remote attacker to cause an interface queue wedge by sending specially crafted UDP packets. The CVSS v3.1 score of 7.5 reflects low attack complexity, no required privileges, and high impact on availability. The attack vector is network, meaning an attacker must have network connectivity to the affected device.
Frequently Asked Questions
Is CVE-2017-6627 being actively exploited?
Yes. CVE-2017-6627 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming active exploitation. The EPSS score of 10.83% (93.3rd percentile) further indicates a high likelihood of ongoing exploitation.
What products are affected by CVE-2017-6627?
CVE-2017-6627 affects Cisco IOS and IOS XE Software. Specifically, affected products include Cisco Ios, Cisco Ios Xe.
How do I fix CVE-2017-6627?
Apply updates per vendor instructions. If immediate patching is not feasible, apply interim mitigations such as access control restrictions and enhanced monitoring to detect exploitation attempts.
How severe is CVE-2017-6627?
CVE-2017-6627 has a CVSS score of 7.5 (HIGH). This is a high-severity denial-of-service vulnerability that can disrupt network operations. While it does not enable code execution, the availability impact on critical network infrastructure makes timely remediation essential.
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