CVE Descriptions

In the Linux kernel, the following vulnerability has been resolved: HID: appleir: fix UAF on pending key_up_timer in remove() appleir_remove() runs hid_hw_stop() before timer_delete_sync(). hid_hw_stop() synchronously unregisters the HID input device via hid_disconnect() -> hidinput_disconnect() -> input_unregister_device(), which drops the last reference and frees the underlying input_dev when no userspace handle holds it open. key_up_tick() reads appleir->input_dev and calls input_report_key() / input_sync() on it. The timer is armed from appleir_raw_event() with a HZ/8 (~125 ms) timeout on every keydown and key-repeat report. If a key was pressed shortly before the device is disconnected, the timer can fire after hid_hw_stop() has freed input_dev but before the teardown drains it. A simple reorder is not sufficient. Putting the timer drain first still leaves a window where a USB URB completion (raw_event) running during hid_hw_stop() can call mod_timer() and re-arm the timer, which then fires after hidinput_disconnect() has freed input_dev. The same URB-completion window also lets raw_event() reach key_up(), key_down() and battery_flat() directly, all of which dereference appleir->input_dev. Introduce a 'removing' flag on struct appleir, gated by the existing spinlock. appleir_remove() sets the flag under the lock and then shuts down the timer with timer_shutdown_sync(), which both drains any in-flight callback and permanently disables further mod_timer() calls. appleir_raw_event() and key_up_tick() bail out early if the flag is set, so no path can arm or run the timer, or dereference appleir->input_dev, after remove() has started tearing down. The keyrepeat and flatbattery branches of appleir_raw_event() previously called into the input layer without holding the spinlock; take it now so the flag check is well-defined. This incidentally closes a pre-existing read-side race on appleir->current_key in the keyrepeat branch. This bug is structurally a sibling of commit 4db2af929279 ("HID: appletb-kbd: fix UAF in inactivity-timer cleanup path") and has been present since the driver was introduced.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-416	Use After Free The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.1	7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H More informations Base: Exploitabilty Metrics The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope Metrics The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact Metrics The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. High There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal Metrics The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental Metrics These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.	nvd@nist.gov