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CVE-2023-20571NVD status: Modified

Ryzen™ 5000 Series Desktop Processor with…: Concurrent Execution using Shared Resource with Improper Synchronization

CVE-2023-20571 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Ryzen™ 5000 Series Desktop Processor with Radeon™ Graphics “Cezanne” from AMD, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Ryzen™ 5000 Series Desktop Processor with Radeon™ Graphics “Cezanne” versions: various. The record does not name a fixed version, so check the vendor advisory. 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 Ryzen 3 5100 Firmware to comboam4v2_1.2.0.b or a later version.
  2. Update Ryzen 3 5300g Firmware to comboam4v2_1.2.0.b or a later version.
  3. Update Ryzen 3 5300ge Firmware to comboam4v2_1.2.0.b or a later version.
  4. Read the advisory on amd.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
AMDRyzen™ 5000 Series Desktop Processor with Radeon™ Graphics “Cezanne”variousNot stated
AMDRyzen™ 7000 Series Desktop Processors “Raphael” XD3variousNot stated
AMDRyzen™ 5000 Series Mobile Processors with Radeon™ Graphics “Cezanne”variousNot stated
AMDAMD Ryzen™ 6000 Series Processors with Radeon™ Graphics "Rembrandt"variousNot stated
AMDAMD Ryzen™ 7035 Series Processors with Radeon™ Graphics “Rembrandt-R”variousNot stated
AMDAMD Ryzen™ 5000 Series Processors with Radeon™ Graphics “Barcelo”variousNot stated
AMDAMD Ryzen™ 7030 Series Mobile Processors with Radeon™ Graphics “Barcelo-R”variousNot stated
AMDRyzen™ 7040 Series Mobile Processors with Radeon™ Graphics “Phoenix” FP7/FP7r2/FP8variousNot stated
AMDRyzen 3 5100 Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 3 5300g Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 3 5300ge Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 5 5500 Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 5 5600g Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 5 5600ge Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 7 5700 Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 7 5700g Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 7 5700ge Firmwarebefore comboam4v2_1.2.0.bcomboam4v2_1.2.0.b
AMDRyzen 5 7500f Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 5 7600 Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 5 7600x Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 7 7700 Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 7 7700x Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 7 7800x3d Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 9 7900 Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0
AMDRyzen 9 7900x Firmwarebefore comboam5_1.0.7.0comboam5_1.0.7.0

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
NetworkCan be exploited remotely over a network, including the internet.
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:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

A race condition in System Management Mode (SMM) code may allow an attacker using a compromised user space to leverage CVE-2018-8897 potentially resulting in privilege escalation.

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

The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How developers prevent this class of flaw

  • In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
  • Use thread-safe capabilities such as the data access abstraction in Spring.
  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

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