scylla: Use of Uninitialized Resource
CVE-2022-29240 is a high-severity use of uninitialized resource vulnerability in scylla from Scylladb, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected scylla versions: < 4.6.7; >= 5.0.0, < 5.0.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.31% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of scylla you run against the affected versions below, and install the vendor's latest release.
- 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
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
- HighSuccess depends on conditions outside the attacker's control.
- 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
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/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 | 8.1 | High | NVD |
Official description
Scylla is a real-time big data database that is API-compatible with Apache Cassandra and Amazon DynamoDB. When decompressing CQL frame received from user, Scylla assumes that user-provided uncompressed length is correct. If user provides fake length, that is greater than the real one, part of decompression buffer won't be overwritten, and will be left uninitialized. This can be exploited in several ways, depending on the privileges of the user. 1. The main exploit is that an attacker with access to CQL port, but no user account, can bypass authentication, but only if there are other legitimate clients making connections to the cluster, and they use LZ4. 2. Attacker that already has a user account on the cluster can read parts of uninitialized memory, which can contain things like passwords of other users or fragments of other queries / results, which leads to authorization bypass and sensitive information disclosure. The bug has been patched in the following versions: Scylla Enterprise: 2020.1.14, 2021.1.12, 2022.1.0. Scylla Open Source: 4.6.7, 5.0.3. Users unable to upgrade should make sure none of their drivers connect to cluster using LZ4 compression, and that Scylla CQL port is behind firewall. Additionally make sure no untrusted client can connect to Scylla, by setting up authentication and applying workarounds from previous point (firewall, no lz4 compression).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Uninitialized Resource
The product uses or accesses a resource that has not been initialized.
How developers prevent this class of flaw
- Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
- Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
- Avoid race conditions (CWE-362) during initialization routines.
More Use of Uninitialized Resource vulnerabilities (CWE-908)
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
- github.com/scylladb/scylla/security/advisories/GHSA-25pq-rrqm-6fmrThird Party Advisory
Patches and release notes
- github.com/scylladb/scylladb/commit/1c2eef384da439b0457b6d71c7e37d7268e471cbThird Party Advisory
- github.com/scylladb/scylladb/issues/11476Issue Tracking, Third Party Advisory
Recent Use of Uninitialized Resource vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
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