CVE-2025-46733
13h13 +00:00
CVE の説明
REE userspace code can panic TAs, leading to fTPM PCR reset and data disclosure
OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. In version 4.5.0, using a specially crafted tee-supplicant binary running in REE userspace, an attacker can trigger a panic in a TA that uses the libutee Secure Storage API. Many functions in libutee, specifically those which make up the Secure Storage API, will panic if a system call returns an unexpected return code. This behavior is mandated by the TEE Internal Core API specification. However, in OP-TEE’s implementation, return codes of secure storage operations are passed through unsanitized from the REE tee-supplicant, through the Linux kernel tee-driver, through the OP-TEE kernel, back to libutee. Thus, an attacker with access to REE userspace, and the ability to stop tee-supplicant and replace it with their own process (generally trivial for a root user, and depending on the way permissions are set up, potentially available even to less privileged users) can run a malicious tee-supplicant process that responds to storage requests with unexpected response codes, triggering a panic in the requesting TA. This is particularly dangerous for TAs built with `TA_FLAG_SINGLE_INSTANCE` (corresponding to `gpd.ta.singleInstance` and `TA_FLAG_INSTANCE_KEEP_ALIVE` (corresponding to `gpd.ta.keepAlive`). The behavior of these TAs may depend on memory that is preserved between sessions, and the ability of an attacker to panic the TA and reload it with a clean memory space can compromise the behavior of those TAs. A critical example of this is the optee_ftpm TA. It uses the kept alive memory to hold PCR values, which crucially must be non-resettable. An attacker who can trigger a panic in the fTPM TA can reset the PCRs, and then extend them PCRs with whatever they choose, falsifying boot measurements, accessing sealed data, and potentially more. The impact of this issue depends significantly on the behavior of affected TAs. For some, it could manifest as a denial of service, while for others, like the fTPM TA, it can result in the disclosure of sensitive data. Anyone running the fTPM TA is affected, but similar attacks may be possible on other TAs that leverage the Secure Storage API. A fix is available in commit 941a58d78c99c4754fbd4ec3079ec9e1d596af8f.CVE の情報
関連する弱点
| 弱点名 | 出典 | |
|---|---|---|
| Improper Handling of Exceptional Conditions The product does not handle or incorrectly handles an exceptional condition. |
メトリクス
| メトリクス | スコア | 深刻度 | CVSS ベクター | 出典 |
|---|---|---|---|---|
| V3.1 | 7.9 | HIGH |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
詳細情報
Base: Exploitabilty MetricsThe 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 MetricsThe 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. Changed An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities. Base: Impact MetricsThe 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. Low Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. Low Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component. Temporal MetricsThe 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 MetricsThese 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. |
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参考資料
Tags : x_refsource_CONFIRM
Tags : x_refsource_MISC
