Horizon Alert
Summary of the vulnerability and why it matters
This issue in MCP Calculate Server allows an attacker to execute arbitrary code by sending specially crafted mathematical expressions. This means unauthorized code could be run on the server, potentially impacting data and operations.
- Enables remote code execution.
- Affects services using the calculation server.
- Requires no special access.
Attack Path
How an attacker could exploit the issue
An attacker can exploit this vulnerability by sending specially crafted mathematical expressions to the MCP Calculate Server. Since the server uses `eval()` without proper sanitization, these expressions can be made to execute arbitrary code on the server, leading to a complete compromise.
- Network access required.
- Target: MCP Calculate Server.
- Send malicious expressions.
Live Threat
Current exploitation, exposure, and threat context
Attackers may target this vulnerability due to its critical severity and the potential for remote code execution. However, the limited scope of MCP Calculate Server, often used in specialized or private environments, might reduce its general appeal for broad exploitation campaigns. Its status as a deferred vulnerability suggests that active, widespread weaponization is less likely at this moment.
- Fixed in version 0.1.1.
- No KEV listing.
- Published recently.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
Teams should prioritize immediately isolating any MCP Calculate Server instances that are accessible from untrusted networks due to the critical remote code execution vulnerability. If isolation is not immediately feasible, implement strict network ingress controls to limit access to only essential internal sources. Focus on upgrading to version 0.1.1 or later as soon as possible to address the root cause.
- Upgrade to version 0.1.1.
- Isolate affected services from untrusted networks.
- Monitor for suspicious network activity.
