CVE-2026-20554 in MT2716
Summary
by MITRE • 11/02/2026
In Modem, there is a possible system crash 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 needed for exploitation. Patch ID: MOLY01911177; Issue ID: MSV-10122.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability identified under issue identifier MSV-10122 and addressed by patch MOLY01911177 represents a critical security flaw within the modem subsystem of mobile devices, specifically involving a missing bounds check during data processing operations. This technical deficiency allows for improper memory access when handling input parameters or network packets received from connected base stations. In modern cellular architectures, the modem firmware is responsible for managing all physical layer and link layer communications between the user equipment and the radio access network. When this subsystem fails to validate the length of incoming buffers against allocated memory limits, it creates a classic buffer overflow condition that can corrupt adjacent memory structures or overwrite critical control data such as return addresses or function pointers. The absence of rigorous input validation in these low-level communication protocols means that malformed packets crafted by an adversary can trigger undefined behavior within the modem processor, potentially leading to a system crash or denial of service state if not exploited further for code execution.
The operational impact of this vulnerability is severe due to its potential for remote privilege escalation without requiring additional execution privileges on the host operating system. An attacker capable of controlling a rogue base station can transmit specially crafted signaling messages that exploit the missing bounds check within the modem firmware. Since cellular modems often operate with elevated hardware-level permissions and have direct access to sensitive device resources, compromising this component effectively bypasses many traditional software-based security controls. The exploitation path requires the user equipment to be connected to or attempt connection with a malicious base station controlled by the attacker. This scenario typically involves setting up an illegal LTE or 5G cell tower that mimics legitimate network infrastructure but injects malicious payloads into the control channel communications. Once the device accepts this rogue signal and processes the malformed data, the resulting memory corruption can allow arbitrary code execution within the modem context, which may then be leveraged to escalate privileges to higher levels of the system architecture or achieve full device compromise.
From a threat modeling perspective, this vulnerability aligns with CWE-125 Out-of-bounds Read and potentially CWE-787 Out-of-bounds Write depending on whether the overflow leads to data leakage or code execution respectively. The attack vector is classified as remote via network access but requires specific physical proximity conditions since cellular signals have limited range compared to internet-based attacks, placing it within the context of ATT&CK technique T1569 System Services where adversaries may exploit system components for lateral movement or persistence. Although user interaction is noted as a factor in exploitation, this likely refers to the necessity of the device accepting the connection from the rogue base station rather than explicit clicks or inputs. This distinction highlights that while passive network exposure triggers the vulnerability, active engagement with malicious infrastructure facilitates successful exploitation. The requirement for physical proximity does not diminish the severity but contextualizes the attack surface as localized yet highly impactful given the privileged nature of modem operations.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements to prevent similar flaws in future firmware releases. Applying the provided patch MOLY01911177 is the primary remediation step, which presumably introduces strict bounds checking routines into the buffer handling logic within the modem driver or protocol stack implementation. Beyond software updates, manufacturers should enforce stricter memory safety practices such as using safe string functions and implementing address space layout randomization where applicable to mitigate exploitation success rates. Network operators can also contribute by deploying detection mechanisms that identify anomalous signaling patterns indicative of rogue base station activity, although this is challenging due to the encrypted nature of modern cellular traffic. End users should remain cautious about connecting to unknown or unsecured networks in public spaces and ensure their device firmware remains up-to-date with vendor security advisories. Regular auditing of modem code against industry standards like MISRA C for embedded systems can further reduce the likelihood of such low-level memory management errors occurring in production builds.