IOS: Improper Authorization
CVE-2023-20186 is a critical-severity improper authorization vulnerability in IOS from Cisco, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected IOS versions: 12.2(58)SE; 12.2(58)SE1; 12.2(58)SE2, 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 0.78% chance of exploitation within 30 days, higher than 57% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of IOS you run against the affected versions below, and install the vendor's latest release.
- 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 | IOS | 12.2(58)SE; 12.2(58)SE1; 12.2(58)SE2; 12.2(58)EX; 12.2(58)EY; 12.2(58)EY1; 12.2(58)EY2; 12.2(58)EZ; and 32 more ranges | Not stated |
| Cisco | Cisco IOS XE Software | 3.7.0S; 3.7.1S; 3.7.2S; 3.7.3S; 3.7.4S; 3.7.5S; 3.7.6S; 3.7.7S; and 32 more ranges | Not stated |
| Cisco | iOS Xe | 3.2.0se; 3.2.1se; 3.2.2se; 3.2.3se; 3.3.0se; 3.3.0sg; 3.3.0xo; 3.3.1se; 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
- 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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.0 | High | CNA (cisco.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
A vulnerability in the Authentication, Authorization, and Accounting (AAA) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to bypass command authorization and copy files to or from the file system of an affected device using the Secure Copy Protocol (SCP). This vulnerability is due to incorrect processing of SCP commands in AAA command authorization checks. An attacker with valid credentials and level 15 privileges could exploit this vulnerability by using SCP to connect to an affected device from an external machine. A successful exploit could allow the attacker to obtain or change the configuration of the affected device and put files on or retrieve files from the affected device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authorization
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
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 IOS
- 8.6 High severity
- 7.7 High severity
- 8.6 High severity
- 9.0 Critical severity
- 7.7 High severity
- 7.7 High severity
Recent Improper Authorization vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.1 High severity
- 9.8 Critical severity
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