CVE-2023-22745
Description
A flaw was found in tpm2-tss, which is an open source software implementation of the Trusted Computing Group (TCG) Trusted Platform Module (TPM) 2 Software Stack (TSS2). In affected versions, Tss2_RC_SetHandler and Tss2_RC_Decode index into the layer_handler with an 8-bit layer number, but the array only has TPM2_ERROR_TSS2_RC_LAYER_COUNT entries. Trying to add a handler for higher-numbered layers or to decode a response code with a layer number, reads/writes past the end of the buffer. This buffer overrun could result in arbitrary code execution. An example attack is a man-in-the-middle (MiTM) bus attack that returns 0xFFFFFFFFFF for the RC. Given the common use case of TPM modules, an attacker must have local access to the target machine with local system privileges, which allows access to the TPM system. Usually, TPM access requires administrative privileges.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.4 | 6.4 | 6.4 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | High | High |
| Privileges Required | High | High | High |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.
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