Cisco IOS Software and Cisco IOS XE Software Denial-of-Service
CVE-2017-6663 is a medium-severity vulnerability in Cisco IOS and IOS XE, with a CVSS 3.1 base score of 6.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Cisco IOS and IOS XE versions: Cisco IOS and IOS XE. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on March 3, 2022, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Cisco IOS and IOS XE you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco IOS and IOS XE | Cisco IOS and IOS XE | Cisco IOS and IOS XE | Not stated |
| Cisco | iOS | 15.2\(3\)e; 15.2\(3\)e1; 15.2\(3\)e2; 15.2\(3\)e3; 15.2\(3\)e4; 15.2\(3\)e5; 15.2\(3a\)e; 15.2\(3a\)e1; and 32 more ranges | Not stated |
| Cisco | iOS Xe | 3.7.0e; 3.7.1e; 3.7.3e; 3.8.0e; 3.8.0ex; 3.8.1e; 3.8.2e; 3.8.3e; and 32 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.5 | Medium | NVD |
| CVSS 3.1 | 6.5 | Medium | CISA (ADP) |
| CVSS 2.0 | 6.1 | Medium | NVD |
Official description
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting in a denial of service (DoS) condition. More Information: CSCvd88936. Known Affected Releases: Denali-16.2.1 Denali-16.3.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6663US Government Resource
Other vulnerabilities in Cisco IOS and IOS XE
- 8.6 High severity
- 8.6 High severity
- 8.6 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.6 High severity
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