Cisco TelePresence Video Communication Server…: Relative Path Traversal
CVE-2022-20754 is a high-severity relative path traversal vulnerability in Cisco TelePresence Video Communication Server (VCS) Expressway from Cisco, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 3.3% chance of exploitation within 30 days, higher than 89% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Telepresence Video Communication Server to 14.0.5 or a later version.
- 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 TelePresence Video Communication Server (VCS) Expressway | Not specified in the record | Not stated |
| Cisco | Telepresence Video Communication Server | before 14.0.5 | 14.0.5 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.0 | Critical | CNA (cisco.com) |
| CVSS 3.1 | 7.2 | High | NVD |
| CVSS 2.0 | 9.0 | High | NVD |
Official description
Multiple vulnerabilities in the API and web-based management interfaces of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker with read/write privileges to the application to write files or execute arbitrary code on the underlying operating system of an affected device as the root user. For more information about these vulnerabilities, see the Details section of this advisory.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Relative Path Traversal
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as.. that can resolve to a location that is outside of that directory.
How developers prevent this class of flaw
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco TelePresence Video Communication Server (VCS) Expressway
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Relative Path Traversal vulnerabilities
- 7.2 High severity
- 9.8 Critical severity
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