Beats: Improper Certificate Validation
CVE-2023-31421 is a high-severity improper certificate validation vulnerability in Beats from Elastic, 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 Beats versions: 8.0.0, 8.9.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Beats you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on discuss.elastic.co 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 |
|---|---|---|---|
| Elastic | Beats | 8.0.0, 8.9.2 | Not stated |
| Elastic | Elastic Agent | 8.0.0, 8.9.2 | Not stated |
| Elastic | APM Server | 8.0.0, 8.9.2 | Not stated |
| Elastic | Fleet Server | 8.0.0, 8.9.2 | Not stated |
| Elastic | Elastic Beats | 8.0.0 through 8.9.2 | Not stated |
| Elastic | Elastic Fleet Server | 8.0.0 through 8.9.2 | 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
- 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 (elastic.co) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
It was discovered that when acting as TLS clients, Beats, Elastic Agent, APM Server, and Fleet Server did not verify whether the server certificate is valid for the target IP address; however, certificate signature validation is still performed. More specifically, when the client is configured to connect to an IP address (instead of a hostname) it does not validate the server certificate's IP SAN values against that IP address and certificate validation fails, and therefore the connection is not blocked as expected.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Beats
- 7.0 High severity
Recent Improper Certificate Validation vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 7.4 High severity
- 7.1 High severity
- 5.5 Medium severity
- 8.1 High severity
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