Splunk Enterprise: Missing Authentication for Critical Functionality
CVE-2023-40598 is a high-severity missing authentication for critical functionality vulnerability in Splunk Enterprise from Splunk, 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 8.2.12, 9.0.6, 9.1.1 as the first without the flaw, so updating Splunk Enterprise to one of those releases or later removes the exposure. 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 Splunk Enterprise to 8.2.12 or 9.0.6 or 9.1.1, whichever matches your release line, or a later version.
- Update Splunk Cloud to 9.0.2305.200 or a later version.
- Update Splunk to 8.2.12 or 9.0.6 or 9.1.1, whichever matches your release line, or a later version.
- Read the advisory on advisory.splunk.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Splunk | Splunk Enterprise | 8.2 up to, but not including, 8.2.12; 9.0 up to, but not including, 9.0.6; 9.1 up to, but not including, 9.1.1 | 8.2.12, 9.0.6, 9.1.1 |
| Splunk | Splunk Cloud | before 9.0.2305.200 | 9.0.2305.200 |
| Splunk | Splunk | before 8.2.12; 9.0.0 up to, but not including, 9.0.6; 9.1.0 up to, but not including, 9.1.1 | 8.2.12, 9.0.6, 9.1.1 |
| Splunk | Splunk Cloud Platform | before 9.0.2305.200 | 9.0.2305.200 |
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 | 8.5 | High | CNA (splunk.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
In Splunk Enterprise versions below 8.2.12, 9.0.6, and 9.1.1, an attacker can create an external lookup that calls a legacy internal function. The attacker can use this internal function to insert code into the Splunk platform installation directory. From there, a user can execute arbitrary code on the Splunk platform Instance.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- 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 libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
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
Other vulnerabilities in Splunk Enterprise
- 9.9 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 9.9 Critical severity
- 8.8 High severity
- 7.2 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 5.3 Medium severity
- 5.3 Medium severity
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