Zyxel security advisory for buffer overflow vulnerability in Realtek eCos SDK

CVE: CVE-2022-27255



Zyxel is aware of a buffer overflow vulnerability in some versions of Realtek’s Software Development Kit (SDK) and assures customers that Zyxel products are NOT affected.


What is the vulnerability?

A stack-based buffer overflow vulnerability was found in the SIP ALG module in some versions of Realtek’s eCos SDK. This could allow a remote unauthenticated attacker to trigger a buffer overflow and then cause a crash or achieve arbitrary code execution via a crafted SIP packet containing malicious SDP data.


What versions are vulnerable—and what should you do?

After a thorough investigation, we can confirm that Zyxel products are NOT affected, because they either do not use a vulnerable SDK version or do not adopt the vulnerable SIP ALG module.


Got a question?

Please contact your local service rep or visit Zyxel’s forum for further information or assistance.


Revision history

2022-08-18: Initial release