Описание
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
A flaw was found in GRUB2. Affected versions of GRUB2 do not use a constant-time algorithm for grub_crypto_memcmp, which can allow side-channel attacks.
Отчет
Due to the extremely limited conditions needed for exploitation, this vulnerability is classified as low severity. Due to GRUB using libgcrypt during HTTPS operations, there is potential for a side-channel attack that could enable an attacker to infer TLS session key information. However, because GRUB runs in a single-threaded context during boot, it eliminates the common attack vector of timing measurements across threads, so it reduces the potential for exploitation in most situations. Additionally, many configurations offload HTTPS/TLS handling to UEFI or do not enable libgcrypt for HTTPS at all, leaving the vulnerable code path unused. Within regulated environments, a combination of the following controls acts as a significant barrier to successfully exploiting a CWE-208: Observable Timing Discrepancy vulnerability and therefore downgrades the severity of this particular CVE from Moderate to Low. The platform enforces hardening guidelines to apply the most restrictive settings necessary for operations. Baseline configurations and system controls ensure secure software states, while least functionality reduces the attack surface by maintaining consistent settings and minimizing timing variations that could expose discrepancies. Domain accounts are configured with lockout policies to reduce the effectiveness of brute-force attacks and prevent attackers from inferring valid credentials through response timing. Event logs are centrally collected and analyzed to detect anomalous timing-based behaviors that may indicate timing attacks. Static code analysis and peer reviews enforce strong input validation and error handling, limiting the introduction of time-based exploits. Additionally, controls such as process isolation and encryption of data at rest contain the impact of successful exploitation by isolating compromised processes and preventing unauthorized data access.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | grub2 | Will not fix | ||
| Red Hat Enterprise Linux 7 | grub2 | Out of support scope | ||
| Red Hat Enterprise Linux 8 | grub2 | Out of support scope | ||
| Red Hat Enterprise Linux 9 | grub2 | Will not fix | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Fix deferred |
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Дополнительная информация
Статус:
EPSS
6.5 Medium
CVSS3
Связанные уязвимости
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorit ...
EPSS
6.5 Medium
CVSS3