CVE-2025-9088
Published: 16 August 2025
Summary
CVE-2025-9088 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac20 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 45.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2025-9088 is a stack-based buffer overflow vulnerability affecting the Tenda AC20 router on firmware version 16.03.08.12. The flaw exists in the save_virtualser_data function within the /goform/formSetVirtualSer file, where manipulation of the argument list triggers the overflow. It is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-121 (Stack-based Buffer Overflow), and CWE-787 (Out-of-bounds Write), with a CVSS v3.1 base score of 8.8.
The vulnerability enables remote exploitation over the network with low attack complexity and requires only low privileges (PR:L), without user interaction. An attacker can send crafted requests to the affected endpoint, leading to a buffer overflow that grants high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H), potentially allowing arbitrary code execution and full device compromise.
VulDB advisories (ctiid.320356, id.320356, submit.632038) detail the issue, and a proof-of-concept Python exploit script is publicly disclosed on GitHub at https://github.com/ZZ2266/.github.io/tree/main/AC20/formSetVirtualSer and https://github.com/ZZ2266/.github.io/tree/main/AC20/formSetVirtualSer#poc-python-exploit-script. No patches or specific mitigation guidance are mentioned in the available references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-28809
Vulnerability details
A vulnerability was found in Tenda AC20 16.03.08.12. This vulnerability affects the function save_virtualser_data of the file /goform/formSetVirtualSer. The manipulation of the argument list leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit has been disclosed…
more
to the public and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in the Tenda AC20 router's web interface (/goform/formSetVirtualSer) enables remote code execution via crafted argument list, facilitating exploitation of public-facing applications and remote services.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requires validation of the argument list inputs to the save_virtualser_data function to prevent stack-based buffer overflows from crafted remote requests.
Implements memory safeguards like stack canaries and non-executable memory to block arbitrary code execution from the stack-based buffer overflow.
Mandates timely flaw remediation to patch the buffer overflow vulnerability in the Tenda AC20 firmware's /goform/formSetVirtualSer endpoint.