UnsafeAccessor: Incorrect Authorization
CVE-2022-31139 is a high-severity incorrect authorization vulnerability in UnsafeAccessor from Karlatemp, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected UnsafeAccessor versions: >= 1.4.0, < 1.7.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.2% chance of exploitation within 30 days, higher than 69% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Unsafe Accessor to 1.7.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Karlatemp | UnsafeAccessor | >= 1.4.0, < 1.7.0 | Not stated |
| Unsafe Accessor Project | Unsafe Accessor | 1.4.0 up to, but not including, 1.7.0 | 1.7.0 |
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
- NoneNo account or login is needed.
- 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
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.9 | Medium | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 4.3 | Medium | NVD |
Official description
UnsafeAccessor (UA) is a bridge to access jdk.internal.misc.Unsafe & sun.misc.Unsafe. Normally, if UA is loaded as a named module, the internal data of UA is protected by JVM and others can only access UA via UA's standard API. The main application can set up `SecurityCheck.AccessLimiter` for UA to limit access to UA. Starting with version 1.4.0 and prior to version 1.7.0, when `SecurityCheck.AccessLimiter` is set up, untrusted code can access UA without limitation, even when UA is loaded as a named module. This issue does not affect those for whom `SecurityCheck.AccessLimiter` is not set up. Version 1.7.0 contains a patch.
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
Advisories
- github.com/Karlatemp/UnsafeAccessor/security/advisories/GHSA-cr6p-23cf-w9g9Third Party Advisory
Patches and release notes
- github.com/Karlatemp/UnsafeAccessor/commit/4ef83000184e8f13239a1ea2847ee401d81585fdThird Party Advisory
- github.com/Karlatemp/UnsafeAccessor/releases/tag/1.7.0Release Notes, Third Party Advisory
Recent Incorrect Authorization vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.6 High severity
- 7.5 High severity
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