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Module thread can get priority higer than txm_module_instance_maximum_priority

Moderate
mrybczyn published GHSA-w8rw-fqgj-9r49 Oct 15, 2025

Package

ThreadX (Eclipse ThreadX)

Affected versions

<= 6.4.2

Patched versions

6.4.3

Description

Summary

In threadx modules, there is protection upon thread creation checking if priority and preemption priority is not higher than txm_module_instance_maximum_priority, but in thread_priority_change and thread_preemption_change there is no check for it

Details

there is an option to control the maximum thread priority and preemption priority.

This option controlled by:

threadx/common_modules/module_manager/src/txm_module_manager_maximum_module_priority_set.c

Line 68 in 7ad78c4

UINT _txm_module_manager_maximum_module_priority_set(TXM_MODULE_INSTANCE *module_instance, UINT priority)

This checked when creating all module threads:

threadx/common_modules/module_manager/src/txm_module_manager_start.c

Lines 123 to 124 in 7ad78c4

if (module_instance -> txm_module_instance_start_stop_priority < module_instance -> txm_module_instance_maximum_priority ||
module_instance -> txm_module_instance_callback_priority < module_instance -> txm_module_instance_maximum_priority)

threadx/common_modules/module_manager/inc/txm_module_manager_dispatch.h

Lines 2030 to 2033 in 7ad78c4

if (extra_parameters[4] < module_instance -> txm_module_instance_maximum_priority)
return(TX_PRIORITY_ERROR);
if (extra_parameters[5] < module_instance -> txm_module_instance_maximum_priority)

But not checked when thread request to change its/other thread priority.

Expected behaviour:

at:

threadx/common_modules/module_manager/inc/txm_module_manager_dispatch.h

Line 2387 in 7ad78c4

static ALIGN_TYPE _txm_module_manager_tx_thread_preemption_change_dispatch(TXM_MODULE_INSTANCE *module_instance, ALIGN_TYPE param_0, ALIGN_TYPE param_1, ALIGN_TYPE param_2)

threadx/common_modules/module_manager/inc/txm_module_manager_dispatch.h

Line 2416 in 7ad78c4

static ALIGN_TYPE _txm_module_manager_tx_thread_priority_change_dispatch(TXM_MODULE_INSTANCE *module_instance, ALIGN_TYPE param_0, ALIGN_TYPE param_1, ALIGN_TYPE param_2)

It will be checked if the requested thread is module thread and if it is to be checked against his module txm_module_instance_maximum_priority value

Impact

thread can have higher priority than allowed and potentially create a denial of service

Severity

Moderate

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 Present
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability High
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:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVE ID

CVE-2025-55079

Weaknesses

Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. Learn more on MITRE.

Credits