Samsung Mobile Devices Improper Input Validation
CVE-2021-25489 is a medium-severity use of externally-controlled format string vulnerability in Samsung Mobile Devices from Samsung, with a CVSS 3.1 base score of 5.5 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version SMR Oct-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 Oct-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(8.1), P(9.0), Q(10.0), R(11.0) up to, but not including, SMR Oct-2021 Release 1 | SMR Oct-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
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 3.3 | Low | CNA (samsung.com) |
| CVSS 3.1 | 5.5 | Medium | NVD |
| CVSS 2.0 | 4.9 | Medium | NVD |
Official description
Assuming radio permission is gained, missing input validation in modem interface driver prior to SMR Oct-2021 Release 1 results in format string bug leading to kernel panic.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Format String
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
How developers prevent this class of flaw
- Choose a language that is not subject to this flaw.
- Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
- Run compilers and linkers with high warning levels, since they may detect incorrect usage.
More Use of Externally-Controlled Format String vulnerabilities (CWE-134)
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: partial).
- 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-2021-25489US 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 Use of Externally-Controlled Format String vulnerabilities
- 8.1 High severity
- 8.0 High severity
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