CyberSecBulletin
CVE-2024-21924NVD status: Deferred

AMD EPYC™ 7002 Processors: Execution with Unnecessary Privileges

CVE-2024-21924 is a high-severity execution with unnecessary privileges vulnerability in AMD EPYC™ 7002 Processors from AMD, with a CVSS 3.1 base score of 8.2 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. There is no confirmed exploitation so far. EPSS estimates a 0.21% 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. Check which version of AMD EPYC™ 7002 Processors you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
AMDAMD EPYC™ 7002 ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ PRO 3000WX Series ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ PRO 5000WX- Series Desktop ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ PRO 7000 WX-Series ProcessorsNot specified in the recordNot stated
AMDAMD EPYC™ Embedded 7002 ProcessorsNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. 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
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (amd.com).

Official description

SMM callout vulnerability within the AmdPlatformRasSspSmm driver could allow a ring 0 attacker to modify boot services handlers, potentially resulting in arbitrary code execution.

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

The underlying weakness: Execution with Unnecessary Privileges

The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.

How developers prevent this class of flaw

  • Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
  • Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting all possible communication channels that could interact with the privileged code, such as a secondary socket that is only intended to be accessed by administrators.
  • Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting all possible communication channels that could interact with the privileged code, such as a secondary socket that is only intended to be accessed by administrators.

More Execution with Unnecessary Privileges vulnerabilities (CWE-250)

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).

References

Recent Execution with Unnecessary Privileges vulnerabilities

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