CVE-2026-20598 in MT2716
Summary
by MITRE • 11/02/2026
In Modem, there is a possible out of bounds read due to an integer overflow. This could lead to remote denial of service, 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: MOLY01755742; Issue ID: MSV-8896.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability described involves an integer overflow condition within a modem component that can result in an out-of-bounds read operation. This type of flaw typically occurs when arithmetic operations exceed the maximum value representable by the allocated data type, causing the resulting memory address calculation to wrap around or point to unintended locations. In the context of cellular network stacks, such errors are particularly critical because they reside in low-level firmware that processes incoming signaling messages from base stations. The specific manifestation here is an out-of-bounds read, which means the system attempts to access memory data outside the bounds of a designated buffer. While this does not immediately imply arbitrary code execution as with write vulnerabilities, it poses significant risks related to information disclosure and service stability depending on what sensitive data resides in adjacent memory regions or how the operating system handles such illegal accesses.
The operational impact centers on remote denial of service capabilities without requiring any user interaction or elevated privileges from the device side. An attacker can exploit this flaw by controlling a rogue base station, often referred to as an IMSI catcher or fake cell tower, and transmitting specially crafted signaling messages that trigger the integer overflow during processing. When the modem processes these malformed packets, the resulting memory access violation likely causes the modem firmware to crash, reset, or enter an unstable state. This effectively disconnects the user equipment from the network, denying service to legitimate users in proximity to the rogue base station. Since no execution privileges are needed on the target device and no user interaction is required, this represents a high-severity threat vector that can be executed remotely by any adversary with access to radio frequency transmission capabilities within range of the vulnerable modem.
From a classification perspective, this vulnerability aligns closely with CWE-190 Integer Overflow or Wraparound, which describes situations where an arithmetic operation produces a result too large for the data type used. The subsequent out-of-bounds read corresponds to CWE-125 Out-of-bounds Read, indicating that the flawed calculation leads to accessing memory beyond allocated limits. In terms of attack tactics and techniques, this scenario maps directly to MITRE ATT&CK technique T1498 Network Denial of Service, specifically under subtechniques involving resource exhaustion or service disruption through protocol exploitation. The use of a rogue base station also touches upon aspects of impersonation attacks where the attacker masquerades as legitimate network infrastructure to deliver malicious payloads at the link layer level.
Mitigation strategies primarily rely on applying the vendor-provided patch identified by MOLY01755742, which addresses the underlying integer overflow logic within the modem firmware. Organizations and users should ensure that device management systems are configured to automatically deploy such security updates as soon as they become available. Additionally, implementing network-level monitoring for anomalous signaling traffic can help detect attempts to exploit this vulnerability in real-time. While user-side controls like disabling automatic network selection may reduce exposure time, the most effective defense remains timely patching of the modem firmware and maintaining up-to-date baseband software versions that include fixes for known stack vulnerabilities.