CyberSecBulletin
CVE-2021-25372Exploited in the wildNVD status: Analyzed

Samsung Mobile Devices Improper Boundary Check

Published Updated By the CyberSecBulletin desk

CVE-2021-25372 is a medium-severity out-of-bounds write vulnerability in Samsung Mobile Devices from Samsung, with a CVSS 3.1 base score of 6.7 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 Mar-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.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Samsung Mobile Devices to SMR Mar-2021 Release 1 or a later version.
  2. CISA's required action: Apply updates per vendor instructions or discontinue use of the product if updates are unavailable
  3. Read the advisory on security.samsungmobile.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Samsung MobileSamsung Mobile Devicesbefore SMR Mar-2021 Release 1SMR Mar-2021 Release 1
SamsungAndroid10.0; 11.0Not 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
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:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.16.1MediumCNA (samsung.com)
CVSS 3.16.7MediumNVD
CVSS 2.07.2HighNVD

Official description

An improper boundary check in DSP driver prior to SMR Mar-2021 Release 1 allows out of bounds memory access.

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. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Samsung Mobile Devices

All Samsung Mobile Devices vulnerabilities

Recent Out-of-bounds Write vulnerabilities

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