xcat-core: Incorrect Authorization
CVE-2023-27486 is a high-severity incorrect authorization vulnerability in xcat-core from Xcat2, 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 xcat-core versions: < 2.16.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.85% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Xcat to 2.16.5 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Xcat2 | xcat-core | < 2.16.5 | Not stated |
| Xcat Project | Xcat | before 2.16.5 | 2.16.5 |
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
- 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 | 8.1 | High | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
xCAT is a toolkit for deployment and administration of computer clusters. In versions prior to 2.16.5 if zones are configured as a mechanism to secure clusters in XCAT, it is possible for a local root user from one node to obtain credentials to SSH to any node in any zone, except the management node of the default zone. XCAT zones are not enabled by default. Only users that use the optional zone feature are impacted. All versions of xCAT prior to xCAT 2.16.5 are vulnerable. This problem has been fixed in xCAT 2.16.5. Users making use of zones should upgrade to 2.16.5. Users unable to upgrade may mitigate the issue by disabling zones or patching the management node with the fix contained in commit `85149c37f49`.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
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 access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied 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
Patches and release notes
Technical write-ups (may include proof of concept)
- github.com/xcat2/xcat-core/issues/7246Exploit, Issue Tracking
Recent Incorrect Authorization vulnerabilities
- 8.1 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 8.5 High severity
- 7.8 High severity
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