CVE-2025-49133

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Last Modified: UTC

Moderate Moderate Impact What does this mean?
5.9 CVSS v3 Base Score

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.

Additional Information

External References

Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2025-49133

Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2025-49133

Content from github.com is not included.https://github.com/stefanberger/libtpms/commit/04b2d8e9afc0a9b6bffe562a23e58c0de11532d1

Content from github.com is not included.https://github.com/stefanberger/libtpms/security/advisories/GHSA-25w5-6fjj-hf8g

Content from trustedcomputinggroup.org is not included.https://trustedcomputinggroup.org/resource/tpm-library-specification

Content from trustedcomputinggroup.org is not included.https://trustedcomputinggroup.org/wp-content/uploads/TPM-2.0-1.83-Part-4-Supporting-Routines-Code.pdf

Affected Packages and Issued Red Hat Security Errata

Products / Services Components State Errata
Red Hat Enterprise Linux 10 libtpms Fixed RHSA-2025:16428
Red Hat Enterprise Linux 8 virt-devel:rhel Fixed RHSA-2025:12527
Red Hat Enterprise Linux 8 virt:rhel Fixed RHSA-2025:12527
Red Hat Enterprise Linux 8 Advanced Virtualization virt:8.2/libtpms Fix deferred
Red Hat Enterprise Linux 8 Advanced Virtualization virt:av/libtpms Fix deferred
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support virt:rhel Fixed RHSA-2025:12234
Red Hat Enterprise Linux 8.6 Telecommunications Update Service virt:rhel Fixed RHSA-2025:12234
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions virt:rhel Fixed RHSA-2025:12234
Red Hat Enterprise Linux 8.8 Telecommunications Update Service virt:rhel Fixed RHSA-2025:12293
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions virt:rhel Fixed RHSA-2025:12293
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Common Vulnerability Scoring System (CVSS) Score Details

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 Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown Red Hat NVD
CVSS v3 Base Score 5.9 5.5
Attack Vector Local Local
Attack Complexity Low Low
Privileges Required Low Low
User Interaction Required None
Scope Changed Unchanged
Confidentiality Impact None None
Integrity Impact None None
Availability Impact High High

CVSS v3 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

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

 For open source software shipped by multiple vendors, the CVSS base scores may vary for each vendor's version depending on the version they ship, how they ship it, the platform, and even how the software is compiled. This makes scoring of vulnerabilities difficult for third-party vulnerability databases such as NVD that only provide a single CVSS base score for each vulnerability. Red Hat scores reflect how a vulnerability affects our products specifically.

For more information, see https://access.redhat.com/solutions/762393.

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
  • "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
  • "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.

What can I do if my product is listed as "Will not fix"?

 A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.

What can I do if my product is listed as "Fix deferred"?

 A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
  • Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.

What is a mitigation?

 A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

 The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

 In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.

My product is listed as "Out of Support Scope". What does this mean?

 When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.