CVE-2024-56738
Description
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.
Statement
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.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Access Control
Technical Impact: Read Application Data; Bypass Protection Mechanism
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