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Improper Input Validation in AKPublic.Verify with attacker-controlled TPM Quote

Moderate
twitchy-jsonp published GHSA-99cg-575x-774p Jan 31, 2022

Package

gomod go-attestation (Go)

Affected versions

< 0.3.3

Patched versions

0.4.0

Description

Impact

An improper input validation vulnerability in go-attestation before 0.3.3 allows local users to provide a maliciously-formed Quote over no/some PCRs, causing AKPublic.Verify to succeed despite the inconsistency. Subsequent use of the same set of PCR values in Eventlog.Verify lacks the authentication performed by quote verification, meaning a local attacker could couple this vulnerability with a maliciously-crafted TCG log in Eventlog.Verify to spoof events in the TCG log, hence defeating remotely-attested measured-boot.

Patches

This issue is resolved in version 0.4.0. If your usage of this library verifies PCRs using multiple quotes, make sure to use the new method AKPublic.VerifyAll() instead of AKPublic.Verify.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVE ID

CVE-2022-0317

Weaknesses

Credits