Cisco Open Source Snort3: Missing Authentication for Critical Functionality
CVE-2026-76524 is a high-severity missing authentication for critical functionality vulnerability in Cisco Open Source Snort3 from Cisco, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Cisco Open Source Snort3 versions: 3.12.2.0; 3.1.2.0; 3.1.3.0, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% 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 Cisco Open Source Snort3 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Open Source Snort3 | 3.12.2.0; 3.1.2.0; 3.1.3.0; 3.1.4.0; 3.1.5.0; 3.1.6.0; 3.1.7.0; 3.1.8.0; and 32 more ranges | 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
- LocalThe attacker needs local access or must trick a user into running something.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
A vulnerability in the control channel socket implementation of Open Source Snort 3 could allow an authenticated, local attacker with low privileges to execute arbitrary commands as the Snort 3 process user. This vulnerability is due to a lack of authentication when a local user connects to the Snort control channel socket. An attacker could exploit this vulnerability by connecting to the Snort 3 control channel socket as a local user. A successful exploit could allow the attacker to execute arbitrary commands as well as read and write Snort 3 process memory.
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
Other references
Other vulnerabilities in Cisco Open Source Snort3
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 9.0 Critical severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 9.0 Critical severity
- 10.0 Critical severity
- 7.5 High severity
- 9.1 Critical severity
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