Cisco IOS XE Software: Interpretation Conflict
CVE-2022-20915 is a high-severity interpretation conflict vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cisco IOS XE Software you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco IOS XE Software | Not specified in the record | Not stated |
| Cisco | iOS Xe | Not specified in the record | 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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:C/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.4 | High | CNA (cisco.com) |
| CVSS 3.1 | 7.4 | High | NVD |
Official description
A vulnerability in the implementation of IPv6 VPN over MPLS (6VPE) with Zone-Based Firewall (ZBFW) of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling of an IPv6 packet that is forwarded from an MPLS and ZBFW-enabled interface in a 6VPE deployment. An attacker could exploit this vulnerability by sending a crafted IPv6 packet sourced from a device on the IPv6-enabled virtual routing and forwarding (VRF) interface through the affected device. A successful exploit could allow the attacker to reload the device, resulting in a DoS condition.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco IOS XE Software
- 8.6 High severity
- 8.6 High severity
- 9.8 Critical severity
- 8.6 High severity
- 8.6 High severity
- 8.6 High severity
Recent Interpretation Conflict vulnerabilities
- 7.5 High severity
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