CVE-2025-49133
Description
A flaw was found in libtpms. A heap buffer overflow can occur in the tpms_parse_pssh function when parsing a malformed Public Signature Key Exchange (PSK) structure. A local attacker can trigger this overflow by providing a crafted PSK structure to the library. This can lead to a denial of service or allow for arbitrary code execution.
Statement
This vulnerability, identified as a potential out-of-bounds read, is triggered by inconsistent parameters within the CryptHmacSign function of the vTPM (virtual Trusted Platform Module). Although the attack is local to the system, it requires user interaction in the form of sending malicious commands to the vTPM. The primary impact is a denial-of-service (DoS) to the virtual machine (VM) by rendering its vTPM unavailable. This prevents the VM from utilizing critical TPM functionality, which can lead to significant operational disruption. While this flaw does not enable arbitrary code execution, the potential for DoS and broader system instability justifies a Moderate severity rating. The requirement for specific user interaction reduces its severity from what would otherwise be an Important classification.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 5.9 | 5.5 | 5.9 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | Required | None | Required |
| Scope | Changed | Unchanged | Changed |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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