CyberSecBulletin
CVE-2024-21980NVD status: Analyzed

3rd Gen AMD EPYC™ Processors: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2024-21980 is a high-severity out-of-bounds write vulnerability in 3rd Gen AMD EPYC™ Processors from AMD, with a CVSS 3.1 base score of 7.9 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. The record lists version MilanPI 1.0.0.D as the first without the flaw, so updating 3rd Gen AMD EPYC™ Processors to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update 3rd Gen AMD EPYC™ Processors to MilanPI 1.0.0.D or a later version.
  2. Update 4th Gen AMD EPYC™ Processors to GenoaPI 1.0.0.C or a later version.
  3. Update AMD EPYC™ Embedded 7003 to EmbMilanPI-SP3 1.0.0.9 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
AMD3rd Gen AMD EPYC™ Processorsvarious up to, but not including, MilanPI 1.0.0.DMilanPI 1.0.0.D
AMD4th Gen AMD EPYC™ Processorsvarious up to, but not including, GenoaPI 1.0.0.CGenoaPI 1.0.0.C
AMDAMD EPYC™ Embedded 7003various up to, but not including, EmbMilanPI-SP3 1.0.0.9EmbMilanPI-SP3 1.0.0.9
AMDAMD EPYC™ Embedded 9003various up to, but not including, EmbGenoaPI-SP5 1.0.0.7EmbGenoaPI-SP5 1.0.0.7
AMDepyc_7003_firmwarebefore milanpi_1.0.0.9_sp3milanpi_1.0.0.9_sp3
AMDepyc_9003_firmwarebefore genoapi_1.0.0.7_sp5genoapi_1.0.0.7_sp5
AMDepyc_7773x_firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDepyc_9754s_firmwarebefore genoapi_1.0.0.cgenoapi_1.0.0.c
AMDEpyc 7203 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7203p Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 72f3 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7303 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7303p Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7313 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7313p Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7343 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 73f3 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7373x Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7413 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7443 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7443p Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 74f3 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7453 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7473x Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d
AMDEpyc 7513 Firmwarebefore milanpi_1.0.0.dmilanpi_1.0.0.d

Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.9HighCNA (amd.com)
CVSS 3.17.9HighNVD

Official description

Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to potentially overwrite a guest's memory or UMC seed resulting in loss of confidentiality and integrity.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

Other vulnerabilities in 3rd Gen AMD EPYC™ Processors

All 3rd Gen AMD EPYC™ Processors vulnerabilities

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