CyberSecBulletin
CVE-2021-25370Exploited in the wildNVD status: Analyzed

Samsung Mobile Devices Memory Corruption

Published Updated By the CyberSecBulletin desk

CVE-2021-25370 is a medium-severity use after free vulnerability in Samsung Mobile Devices from Samsung, with a CVSS 3.1 base score of 4.4 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 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 November 8, 2022, 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.
  3. Read the advisory on security.samsungmobile.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Samsung MobileSamsung Mobile DevicesSelected O(8.X), P(9.0), Q(10.0), R(11.0) up to, but not including, SMR Mar-2021 Release 1SMR Mar-2021 Release 1
SamsungAndroid8.0; 8.1; 9.0; 10.0; 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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.16.1MediumCNA (samsung.com)
CVSS 3.14.4MediumNVD
CVSS 2.04.9MediumNVD

Official description

An incorrect implementation handling file descriptor in dpu driver prior to SMR Mar-2021 Release 1 results in memory corruption leading to kernel panic.

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

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

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 Use After Free vulnerabilities

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