CVE-2026-26333: Calero VeraSMART < 2022 R1 .NET Remoting Arbitrary File Read Leading to ViewState RCE

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-13 · updated 2026-06-17
Weakness: CWE-306

Description

Calero VeraSMART versions prior to 2022 R1 expose an unauthenticated .NET Remoting HTTP service on TCP port 8001. The service publishes default ObjectURIs (including EndeavorServer.rem and RemoteFileReceiver.rem) and permits the use of SOAP and binary formatters with TypeFilterLevel set to Full. An unauthenticated remote attacker can invoke the exposed remoting endpoints to perform arbitrary file read and write operations via the WebClient class. This allows retrieval of sensitive files such as WebRoot\\web.config, which may disclose IIS machineKey validation and decryption keys. An attacker can use these keys to generate a malicious ASP.NET ViewState payload and achieve remote code execution within the IIS application context. Additionally, supplying a UNC path can trigger outbound SMB authentication from the service account, potentially exposing NTLMv2 hashes for relay or offline cracking.

Affected products

Calero VeraSMART: before 2022.0; 2022.0 — fixed in 2022.0

How to fix

Upgrade to a fixed version: Calero VeraSMART 2022.0. Check the vendor advisory for mitigations.

References

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