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NVD / CVE Program· CNA Linux

CVE-2024-35803: x86/efistub: Call mixed mode boot services on the firmware's stack

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2149f8a56e2ed345c7a4d022a79f6b8fc53ae926, 725351c036452b7db5771a7bed783564bc4b99cc, 930775060ca348b8665f60eef14b204172d14f31.

Low priority for now. Upgrade to Linux Linux 2149f8a56e2ed345c7a4d022a79f6b8fc53ae926, 725351c036452b7db5771a7bed783564bc4b99cc, 930775060ca348b8665f60eef14b204172d14f31 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: x86/efistub: Call mixed mode boot services on the firmware's stack Normally, the EFI stub calls into the EFI boot services using the stack that was live when the stub was entered. According to the UEFI spec, this stack needs to be at least 128k in size - this might seem large but all asynchronous processing and event handling in EFI runs from the same stack and so quite a lot of space may be used in practice. In mixed mode, the situation is a bit different: the bootloader calls the 32-bit EFI stub entry point, which calls the decompressor's 32-bit entry point, where the boot stack is set up, using a fixed allocation of 16k. This stack is still in use when the EFI stub is started in 64-bit mode, and so all calls back into the EFI firmware will be using the decompressor's limited boot stack. Due to the placement of the boot stack right after the boot heap, any stack overruns have gone unnoticed. However, commit 5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code") moved the definition of the boot heap into C code, and now the boot stack is placed right at the base of BSS, where any overruns will corrupt the end of the .data section. While it would be possible to work around this by increasing the size of the boot stack, doing so would affect all x86 systems, and mixed mode systems are a tiny (and shrinking) fraction of the x86 installed base. So instead, record the firmware stack pointer value when entering from the 32-bit firmware, and switch to this stack every time a EFI boot service call is made.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 17, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-35803

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 6.1.84
  • linux linux kernel6.2 and later · before 6.6.24
  • linux linux kernel6.7 and later · before 6.7.12
  • linux linux kernel6.8 and later · before 6.8.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.15affected
    • b8ff87a6158886771677e6dc8139bac6e3cba717 and later · before 2149f8a56e2ed345c7a4d022a79f6b8fc53ae926affected · git
    • b8ff87a6158886771677e6dc8139bac6e3cba717 and later · before 930775060ca348b8665f60eef14b204172d14f31affected · git
    • b8ff87a6158886771677e6dc8139bac6e3cba717 and later · before fba7ee7187581b5bc222003e73e2592b398bb06daffected · git
    • b8ff87a6158886771677e6dc8139bac6e3cba717 and later · before 725351c036452b7db5771a7bed783564bc4b99ccaffected · git
    • b8ff87a6158886771677e6dc8139bac6e3cba717 and later · before cefcd4fe2e3aaf792c14c9e56dab89e3d7a65d02affected · git
    • before 3.15not affected · semver
    • 6.1.84 and later · up to and including 6.1.*not affected · semver
    • 6.6.24 and later · up to and including 6.6.*not affected · semver
    • 6.7.12 and later · up to and including 6.7.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.85-16.1.85-1
Debian:13linuxbefore 6.7.12-16.7.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-35800May 17, 2024 · efi: fix panic in kdump kernel
    22Monitor
  • ← EarlierCVE-2024-35801May 17, 2024 · x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
    22Monitor
  • Later →CVE-2024-35804May 17, 2024 · KVM: x86: Mark target gfn of emulated atomic instruction as dirty
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2149f8a56e2ed345c7a4d022a79f6b8fc53ae926Vendor (CNA)
Linux Linux725351c036452b7db5771a7bed783564bc4b99ccVendor (CNA)
Linux Linux930775060ca348b8665f60eef14b204172d14f31Vendor (CNA)
Linux Linuxcefcd4fe2e3aaf792c14c9e56dab89e3d7a65d02Vendor (CNA)
Linux Linuxfba7ee7187581b5bc222003e73e2592b398bb06dVendor (CNA)
debian:linux6.1.85-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records