Description
PCR14 is not in the list of PCRs that seal/unseal the “vault” key, but
due to the change that was implemented in commit
“7638364bc0acf8b5c481b5ce5fea11ad44ad7fd4”, fixing this issue alone would not solve the
problem of the config partition not being measured correctly.
Also, the “vault” key is sealed/unsealed with SHA1 PCRs instead of
SHA256.
This issue was somewhat mitigated due to all of the PCR extend functions
updating both the values of SHA256 and SHA1 for a given PCR ID.
However, due to the change that was implemented in commit
“7638364bc0acf8b5c481b5ce5fea11ad44ad7fd4”, this is no longer the case for PCR14, as
the code in “measurefs.go” explicitly updates only the SHA256 instance of PCR14, which
means that even if PCR14 were to be added to the list of PCRs sealing/unsealing the “vault”
key, changes to the config partition would still not be measured.
An attacker could modify the config partition without triggering the measured boot, this could
result in the attacker gaining full control over the device with full access to the contents of the
encrypted “vault”
Understanding This Vulnerability
This Common Vulnerabilities and Exposures (CVE) entry provides detailed information about a security vulnerability that has been publicly disclosed. CVEs are standardized identifiers assigned by MITRE Corporation to track and catalog security vulnerabilities across software and hardware products.
The severity rating (HIGH) indicates the potential impact of this vulnerability based on the CVSS (Common Vulnerability Scoring System) framework. Higher severity ratings typically indicate vulnerabilities that could lead to more significant security breaches if exploited. Security teams should prioritize remediation efforts based on severity, exploit availability, and the EPSS (Exploit Prediction Scoring System) score, which predicts the likelihood of exploitation in the wild.
If this vulnerability affects products or systems in your infrastructure, we recommend reviewing the affected products section, checking for available patches or updates from vendors, and implementing recommended workarounds or solutions until a permanent fix is available. Organizations should also monitor security advisories and threat intelligence feeds for updates about active exploitation of this vulnerability.