Skip to content

Permissions CA is not verified

Low
MiguelCompany published GHSA-w33g-jmm2-8983 Feb 11, 2025

Package

No package listed

Affected versions

<3.2.0

Patched versions

2.6.10, 2.10.7, 2.14.5, 3.0.2, 3.1.2, 3.2.0

Description

Summary

Per design PermissionsCA is not full chain validated. Nor the expiration date is validated.
Access control plugin validates only the S/MIME signature which causes an expired PermissionsCA to be taken as valid.

Details

The fact that PermissionsCA is not being validated implies that it's up to the user to set up a certificate management process in order to guarantee security. With this into account it makes sense then, imho, to concatenate certificates in order to preserve the chain. In fact this is mandatory for IdentityCA otherwise I get this authentication error with unable to get issuer certificate message. In other words, if I do not concatenate the RootCA to IdentityCA certificate I can't create a Participant.
And here comes the issue, if I do the same process with PermissionsCA, assuming it's another intermediate CA issued by RootCA, the system would fail because this validation with sk_x509_num() not allowing the certificate store to hold more than one certificate, which would happen in this scenario: PermissionsCA and RootCA. Is there any reason behind this logic? To me there are 2 main reasons why this should be allowed:

  1. It maintains consistency related to IdentityCA

Let's remember IdentityCA needs to be fully chained in order to get issuer certificate.

  1. Since we stablished that is up to the user to validate PermissionsCA (like expiration dates) because the Access Control plugin does not, by design, it's far more convenient to have it fully-chained.

Also according to Secure DDS spec PermissionsCA don't need to be self-signed so there is no problem with that.

All the details provided above are based on my experience using Fast-DDS (2.6.9) while working with ROS 2 and trying different PKI architectures. Please correct me if I made any mistake on something.

PoC

I'm working with ROS 2 Humble, using fastrtps v2.6.9.
I would happily share some PoC (basically how to create some certificates, not much needed for the PoC tbh) if you decide this is the right place to discuss it.

Impact

Even though this issue is responsible for:

  1. allowing governance/permissions from an expired PermissionsCA
  2. having the system crash when PermissionsCA is not self-signed and contains the full-chain. This was hard to debug because no error was shown, that lead me to create this PR.
    the impact is low.

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Local
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N

CVE ID

CVE-2025-24807

Weaknesses

No CWEs

Credits