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CVE Record

CVE-2024-56681: crypto: bcm - add error check in the ahash_hmac_init function

In the Linux kernel, the following vulnerability has been resolved: crypto: bcm - add error check in the ahash_hmac_init function The ahash_init functions may return fails. The ahash_hmac_init should not return ok when ahash_init returns error. For an example, ahash_init will return -ENOMEM when allocation memory is error.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux Broadcom cryptography component can report successful HMAC setup even when its underlying hash initialization failed, including during memory-allocation failure. That incorrect success signal may let later processing continue from an invalid state. The supplied assessment rates potential confidentiality, integrity, and availability impact as high, but provides no demonstrated attack scenario.

Executive priority

Treat this as a high-priority kernel maintenance issue, especially on shared systems or hosts executing untrusted workloads. It is not evidence of an emergency internet-wide threat because exploitation requires local access and none is documented. Patch through normal expedited kernel deployment after compatibility testing, using vendor-specific corrected-package information.

Technical view

The bcm crypto driver's ahash_hmac_init function failed to propagate errors returned by ahash_init. The documented example is -ENOMEM. Upstream stable commits add the missing error check. CVSS 3.1 is 7.8: local access, low complexity, low privileges, no user interaction, unchanged scope, and high potential impact across confidentiality, integrity, and availability.

Likely exposure

Exposure is limited to systems running an affected Linux kernel with the relevant bcm cryptographic code present and reachable. The bundle lists affected releases from 4.11 through 6.13, alongside branch-specific correction commits, but its version presentation is ambiguous. Confirm status using the kernel or distribution vendor's exact package guidance.

Exploitation context

No active exploitation is established: this CVE is not identified as KEV, and the supplied sources provide no evidence of exploitation or public proof of concept. The CVSS vector requires local, low-privileged access. The bundle does not establish practical reachability, reliability, or the conditions needed to turn failed initialization into security impact.

Researcher notes

The central defect is error-propagation failure in ahash_hmac_init. The source bundle documents -ENOMEM as one trigger but does not describe subsequent invalid state, reachable call paths, affected Broadcom hardware, or a demonstrated confidentiality, integrity, or availability consequence. The 7.8 score therefore expresses potential impact; practical exploitability remains insufficiently evidenced.

Mitigation direction

  • Install a vendor-supported kernel containing the applicable upstream stable correction.
  • Use distribution security advisories to identify the corrected package for each deployed release.
  • Prioritize multi-user and untrusted-workload systems because the supplied vector requires local low-privileged access.
  • Apply normal reboot procedures and confirm the corrected kernel is running.

Validation and detection

  • Inventory running kernel and package versions across Linux systems.
  • Determine whether the bcm cryptographic driver is built, loaded, or used on each system.
  • Compare vendor changelogs with CVE-2024-56681 and the applicable stable correction commit.
  • After remediation, verify systems booted into the corrected kernel package.
  • Record exceptions where vendor affected-version guidance remains unavailable or ambiguous.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2024-56681 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
1ADP providers
12Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2024-56681Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2, 9d12ba86f818aa9cfe9f01b750336aa441f2ffa2unaffected
LinuxLinux4.11, 0, 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13affected
Weakness

CWE details

No CWE listed

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