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CVE-2023-20577NVD status: Awaiting Analysis

2nd Gen AMD EPYC™ Processors: Stack-based Buffer Overflow

CVE-2023-20577 is a high-severity stack-based buffer overflow vulnerability in 2nd Gen AMD EPYC™ Processors from AMD, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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 2nd Gen AMD EPYC™ Processors you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
AMD2nd Gen AMD EPYC™ ProcessorsNot specified in the recordNot stated
AMD3rd Gen AMD EPYC™ ProcessorsNot specified in the recordNot stated
AMD4th Gen AMD EPYC™ ProcessorsNot specified in the recordNot stated
AMDAMD Instinct™ MI300ANot specified in the recordNot stated
AMDAMD Ryzen™ 3000 Series Desktop ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ 5000 Series Desktop ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ 5000 Series Desktop Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 7000 Series ProcessorsNot specified in the recordNot stated
AMDAMD Athlon™ 3000 Series Desktop Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 4000 Series Desktop Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ 3000 Series ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ PRO 3000WX Series ProcessorsNot specified in the recordNot stated
AMDAMD Ryzen™ Threadripper™ PRO 5000WX ProcessorsNot specified in the recordNot stated
AMDAMD Athlon™ 3000 Series Mobile Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 3000 Series Mobile Processor with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 4000 Series Mobile Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 5000 Series Mobile Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 7020 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 6000 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 7035 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 5000 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 3000 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 7040 Series Processors with Radeon™ GraphicsNot specified in the recordNot stated
AMDAMD Ryzen™ 7045 Series Mobile ProcessorsNot specified in the recordNot stated
AMDAMD EPYC™ Embedded 3000Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 9 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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
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:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (amd.com).

Official description

A heap overflow in SMM module may allow an attacker with access to a second vulnerability that enables writing to SPI flash, potentially resulting in arbitrary code execution.

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

The underlying weakness: Stack-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the stack.

How developers prevent this class of flaw

  • 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.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Implement and perform bounds checking on input.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

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

Other vulnerabilities in 2nd Gen AMD EPYC™ Processors

All 2nd Gen AMD EPYC™ Processors vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

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