Cisco SD-WAN vManage: Incorrect Permission Assignment for Critical Resource
CVE-2023-20254 is a high-severity incorrect permission assignment for critical resource vulnerability in Cisco SD-WAN vManage from Cisco, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Cisco SD-WAN vManage versions: 17.2.6; 17.2.7; 17.2.8, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.83% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Sd-wan Manager to 20.6.3.4 or 20.9.3.2 or 20.10.1.2 or 20.11.1.2, whichever matches your release line, or a later version.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco SD-WAN vManage | 17.2.6; 17.2.7; 17.2.8; 17.2.9; 17.2.10; 17.2.4; 17.2.5; 18.3.1.1; and 32 more ranges | Not stated |
| Cisco | catalyst_sd-wan_manager | 17.2.10 through 20.9.3.1 | Not stated |
| Cisco | Sd-wan Manager | before 20.6.3.4; 20.7 up to, but not including, 20.9.3.2; 20.10 up to, but not including, 20.10.1.2; 20.11 up to, but not including, 20.11.1.2 | 20.6.3.4, 20.9.3.2, 20.10.1.2, 20.11.1.2 |
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
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.2 | High | CNA (cisco.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
A vulnerability in the session management system of the Cisco Catalyst SD-WAN Manager multi-tenant feature could allow an authenticated, remote attacker to access another tenant that is being managed by the same Cisco Catalyst SD-WAN Manager instance. This vulnerability requires the multi-tenant feature to be enabled. This vulnerability is due to insufficient user session management within the Cisco Catalyst SD-WAN Manager system. An attacker could exploit this vulnerability by sending a crafted request to an affected system. A successful exploit could allow the attacker to gain unauthorized access to information about another tenant, make configuration changes, or possibly take a tenant offline causing a denial of service condition.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
How developers prevent this class of flaw
- When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
- Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources.
- During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
More Incorrect Permission Assignment for Critical Resource vulnerabilities (CWE-732)
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 SD-WAN vManage
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.1 Critical severity
- 8.1 High severity
- 8.8 High severity
Recent Incorrect Permission Assignment for Critical Resource vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 9.9 Critical severity
- 7.8 High severity
- 7.2 High severity
- 8.8 High severity
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