Rule Document 1:66978

Rule Category

SERVER-OTHER -- Snort has detected traffic exploiting vulnerabilities in a server in the network.

Alert Message

SERVER-OTHER JetBrains TeamCity remote code execution attempt

Rule Explanation

This rule looks for HTTP POST requests to the "/app/agents/v1/commands/error" endpoint that contain serialized Java objects referencing a known deserialization gadget class. Successful exploitation may allow an attacker to execute arbitrary code on the server.

What To Look For

This rule fires on attempts to exploit an insecure deserialization vulnerability in JetBrains TeamCity servers.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

Rule Groups

MITRE::ATT&CK Framework::Enterprise::Initial Access::Exploit Public-Facing Application

Adversaries may attempt to take advantage of a weakness in an Internet-facing computer or program using software, data, or commands in order to cause unintended or unanticipated behavior. The weakness in the system can be a bug, a glitch, or a design vulnerability. These applications are often websites, but can include databases (like SQL), standard services (like SMB or SSH), network device administration and management protocols (like SNMP and Smart Install), and any other applications with Internet accessible open sockets, such as web servers and related services.

Vulnerability::Severity::High

Vulnerability::Severity::Critical

CVE

CVE-2026-63077

Additional Links

jetbrains.com/privacy-security/issues-fixed/

Rule Vulnerability

Insecure Deserialization

Insecure Deserialization relates to web application security. Applications turn an object into data through serialization; the reverse of that process, deserialization, can be vulnerable to attacks when the application trusts the data that is being deserialized. Serialized data is machine readable and not encrypted; serialized user-supplied data should not be trusted. Deserialization attacks can lead to remote code execution.

CVE Additional Information

This product uses data from the NVD API but is not endorsed or certified by the NVD.

CVE-2026-63077

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