CVE-2025-7921
Published: 21 July 2025
Summary
CVE-2025-7921 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Org (inferred from references). Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 19.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
Certain modem models from Askey contain a stack-based buffer overflow vulnerability tracked as CVE-2025-7921 and CWE-121. The flaw resides in the modem firmware and permits unauthenticated remote attackers to manipulate program control flow, with the potential to execute arbitrary code on affected devices.
The vulnerability is exploitable over the network without credentials or user interaction, as reflected in its CVSS 4.0 score of 9.3. An attacker who supplies a crafted payload can achieve full control of the execution path, leading to remote code execution on the modem.
Public advisories from Taiwan’s CERT (TW-CERT) describe the issue and list the impacted Askey models; the references do not detail specific patches or configuration workarounds in the supplied information. The associated EPSS score remains low and unchanged at 0.0138, indicating limited observed exploitation interest to date.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-22058
Vulnerability details
Certain modem models developed by Askey has a Stack-based Buffer Overflow vulnerability, allowing unauthenticated remote attackers to control the program's execution flow and potentially execute arbitrary code.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct unauthenticated RCE via network-accessible buffer overflow on public-facing modem service enables remote exploitation of exposed applications.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the stack-based buffer overflow vulnerability through timely application of vendor patches or firmware updates.
Implements memory protections like stack canaries, ASLR, and non-executable memory to block control flow hijacking from stack buffer overflows.
Enforces input validation and bounds checking on unauthenticated remote network inputs to prevent exploitation of the buffer overflow.