GitLab: Incorrect Authorization
CVE-2023-5356 is a high-severity incorrect authorization vulnerability in GitLab, 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. The record lists versions 16.5.6, 16.6.4, 16.7.2 as the first without the flaw, so updating GitLab to one of those releases or later removes the exposure. 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 GitLab to 16.5.6 or 16.6.4 or 16.7.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| GitLab | GitLab | 8.13 up to, but not including, 16.5.6; 16.6 up to, but not including, 16.6.4; 16.7 up to, but not including, 16.7.2 | 16.5.6, 16.6.4, 16.7.2 |
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 | 7.3 | High | CNA (gitlab.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
Incorrect authorization checks in GitLab CE/EE from all versions starting from 8.13 before 16.5.6, all versions starting from 16.6 before 16.6.4, all versions starting from 16.7 before 16.7.2, allows a user to abuse slack/mattermost integrations to execute slash commands as another user.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- hackerone.com/reports/2188868Permissions Required
Other vulnerabilities in GitLab
- 7.1 High severity
- 8.2 High severity
- 7.5 High severity
- 10.0 Critical severity
- 10.0 Critical severity
- 7.3 High severity
Recent Incorrect Authorization vulnerabilities
- 7.2 High severity
- 9.8 Critical severity
- 7.6 High severity
- 8.2 High severity
- 8.2 High severity
- 8.8 High severity
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