AI agents use snow_encode_base64 to create or update resources in Serac — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Serac environment.
Base64 encoding is a reversible transformation that prepares data for transmission or storage. While local and not inherently destructive, it modifies data in a way that enables subsequent Write operations (like attachment uploads). The tool itself does not execute queries, delete data, or move money.
From the tool's definition Encodes a UTF-8 string as Base64 'for embedding binary-ish data in JSON payloads (e.g. attachment uploads)'. The description indicates this transforms and prepares data for upload/submission.
Attacks that exploit this kind of access
Encode a UTF-8 string as Base64. Local operation — no ServiceNow call. Handy for embedding binary-ish data in JSON payloads (e.g. attachment uploads). It is categorised as a Write tool in the Serac MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Serac MCP server in PolicyLayer and add a rule for snow_encode_base64: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Serac. Nothing to install.
snow_encode_base64 is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the snow_encode_base64 rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for snow_encode_base64. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
snow_encode_base64 is provided by the Serac MCP server (serac-labs/serac). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
snow_encode_base64 is one line of Serac's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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