All news with #viewstate deserialization tag

Sitecore ViewState Deserialization Zero-Day Advisory

🔒 Mandiant and Sitecore investigated an active ViewState deserialization exploit that allowed remote code execution on internet-facing Sitecore instances that used publicly exposed sample ASP.NET machine keys. Tracked as CVE-2025-53690, the vulnerability enabled attackers to craft malicious __VIEWSTATE payloads, deploy a reconnaissance backdoor (WEEPSTEEL), and stage tunneling and remote access tooling. Sitecore has updated deployments to auto-generate unique machine keys and notified affected customers; Mandiant recommends rotating keys, enabling ViewState MAC, and encrypting secrets in web.config to mitigate similar attacks.