Description

In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01778993; Issue ID: MSV-8898.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-10-05T02:16:50.393Z",
  "pubdate": "2026-10-05T02:16:50.393Z",
  "executiveSummary": "A critical security vulnerability has been identified in the modem firmware, characterized as an out-of-bounds (OOB) write due to insufficient bounds validation. This flaw allows a remote attacker to gain unauthorized privileges on the target device.\nThe vulnerability is exploitable when a User Equipment (UE) connects to a malicious base station (rogue base station) controlled by an adversary. Successful exploitation facilitates remote escalation of privilege without requiring user interaction or elevated execution permissions.\nGiven the nature of modem firmware, which operates at a low level within the communication stack, this vulnerability poses a severe risk to device integrity and confidentiality. The impact includes the potential for arbitrary code execution within the context of the modem processor, which may allow an attacker to bypass cellular security protections, intercept communications, or compromise the host system through inter-processor communication channels.\nAffected systems include the specific modem component associated with Patch ID: MOLY01778993 and Issue ID: MSV-8898.",
  "technicalDetails": "The root cause of this vulnerability is the absence of rigorous bounds checking mechanisms during the processing of incoming radio resource control or signaling data within the modem firmware. When the modem handles protocol-specific packets from the base station, it fails to validate the size of input data against the allocated buffer size. This failure leads to an out-of-bounds write condition.\nThe attack flow begins when an attacker deploys a rogue base station that mimics a legitimate cellular provider. The victim device, scanning for available cellular networks, authenticates and connects to this rogue base station. Once the connection is established, the attacker transmits a specially crafted sequence of signaling packets designed to trigger the vulnerable code path.\nAs the modem firmware parses these packets, the lack of input validation allows the malicious payload to write data beyond the designated memory region. This memory corruption can be leveraged to overwrite adjacent critical data structures, function pointers, or return addresses in the modem's memory space.\nBy carefully controlling the content of the out-of-bounds write, an attacker can redirect the program execution flow to an attacker-controlled memory location. This leads to arbitrary code execution within the modem's execution environment. Because the modem typically interfaces with the Application Processor (AP) via shared memory or inter-processor communication (IPC) protocols, successful exploitation can lead to a privilege escalation that extends beyond the modem firmware and potentially into the main operating system of the device.\nNo user interaction is required for this exploitation, as it occurs autonomously during the initial network handshake and registration process. The vulnerability resides within the modem's protocol stack, exposing the device to any attacker capable of establishing a rogue radio environment. The lack of authentication requirements at the protocol layer significantly increases the feasibility of this attack, as the device is designed to trust signaling information received during the attachment process. Post-exploitation, the attacker maintains control over the modem's communication capabilities, allowing for ongoing reconnaissance, data exfiltration, or further persistence within the device architecture."
}