Samsung Mobile Devices Race Condition
CVE-2021-25394 is a medium-severity concurrent execution using shared resource with improper synchronization vulnerability in Samsung Mobile Devices from Samsung, with a CVSS 3.1 base score of 6.4 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 SMR MAY-2021 Release 1 as the first without the flaw, so updating Samsung Mobile Devices to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on June 29, 2023, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Samsung Mobile Devices to SMR MAY-2021 Release 1 or a later version.
- CISA's required action: Apply updates per vendor instructions or discontinue use of the product if updates are unavailable
- Read the advisory on security.samsungmobile.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Samsung Mobile | Samsung Mobile Devices | O(8.x), P(9.0), Q(10.0), R(11.0) up to, but not including, SMR MAY-2021 Release 1 | SMR MAY-2021 Release 1 |
| Samsung | Android | 8.1; 9.0; 10.0; 11.0 | Not 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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.4 | Medium | CNA (samsung.com) |
| CVSS 3.1 | 6.4 | Medium | NVD |
| CVSS 2.0 | 4.4 | Medium | NVD |
Official description
A use after free vulnerability via race condition in MFC charger driver prior to SMR MAY-2021 Release 1 allows arbitrary write given a radio privilege is compromised.
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).
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-25394US Government Resource
Other vulnerabilities in Samsung Mobile Devices
- 8.6 High severity
- 8.6 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 6.4 Medium severity
Samsung Mobile Devices Race Condition Exploited
- 8.8 High severity
Google Chromium Race Condition Exploited
- 8.1 High severity
- 8.1 High severity
- 7.0 High severity
Linux Kernel Race Condition Exploited
- 6.9 Medium severity
Linux Kernel Race Condition Exploited
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