Overview
A significant security vulnerability, CVE-2025-27891, has been discovered affecting various Samsung Mobile Processor, Wearable Processor, and Modem models. The vulnerability is a result of insufficient length checks, which could potentially lead to out-of-bounds reads via malformed NAS packets. This vulnerability is of great concern due to the widespread use of Samsung processors in many popular mobile and wearable devices. A successful exploit could lead to system compromise or data leakage, posing significant risks for user privacy and security.
Vulnerability Summary
CVE ID: CVE-2025-27891
Severity: Critical (CVSS Score: 9.1)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
Samsung Mobile Processor Exynos | 980, 990, 850, 1080, 2100, 1280, 2200, 1330, 1380, 1480, 2400
Samsung Wearable Processor Exynos | W920, W930, W1000
Samsung Modem Exynos | 5123, 5300, 5400
How the Exploit Works
The exploit takes advantage of the lack of length check in the Exynos processors. By sending malformed Network Access System (NAS) packets, an attacker can provoke out-of-bounds reads. This happens as the processor’s function, which handles these packets, does not appropriately verify their length. As a result, an attacker can manipulate the packets to cause the processor to read data beyond its intended boundary. This could potentially lead to system compromise or data leakage.
Conceptual Example Code
Here is a conceptual example of how an attacker might send a malformed NAS packet to exploit this vulnerability:
POST /NAS_packet HTTP/1.1
Host: target.example.com
Content-Length: [Insert an overly large value]
{ "malicious_payload": "..." }In the above example, the `Content-Length` header is set to an overly large value, and the request body contains a malicious payload. This malformed NAS packet could trigger an out-of-bounds read, exploiting the vulnerability.
Mitigation Guidance
Samsung has released a patch to address this vulnerability. All users of the affected products are strongly advised to apply this patch as soon as possible. In the interim, users can use Web Application Firewalls (WAF) or Intrusion Detection Systems (IDS) to provide temporary mitigation against potential exploits.