Title: CVE-2025-55319 — When Agentic AI Meets VS Code: How AI “agents” can open a path to remote code execution (and what developers must do now)
Executive summary
- Microsoft’s Security Response Center lists CVE-2025-55319 as a vulnerability affecting agentic AI integrations and Visual Studio Code. The vendor entry is the canonical reference point for the record. (msrc.microsoft.com)
- Public reporting about this exact CVE is limited at the time of writing; however the technical pattern described (AI agent prompt/command injection that results in configuration changes or execution of shell commands) matches a wave of recently disclosed, high‑impact vulnerabilities across Claude Code, Cursor and other “agentic” tooling. Those precedents show how small design choices — auto-approve settings, writable per‑workspace config files, and naive tool invocation prompts — can be chained into remote code execution. (nvd.nist.gov)
- This article explains the likely attack chain and practical mitigations for developers and admins, suggests detection/hunting steps, and provides a concise roadmap to reduce risk while vendors publish patches or advisories.
Agentic AI tooling — IDE extensions, assistant agents that can edit files and invoke tools (terminals, synthesize API calls, or write config files) — is useful because it automates repetitive developer tasks. But when an agent can (a) ingest attacker‑controlled content, (b) write or edit local configuration files without strict confirmation, and (c) invoke tool APIs that run shell commands, the net effect is a novel attack surface that can be used to obtain code execution under the user’s privileges. Several recent CVEs demonstrate this pattern in the wild and at scale, making any similar reports urgent. (thehackernews.com)
What the MSRC entry tells us
Microsoft’s Security Update Guide hosts the CVE entry you referenced (CVE-2025-55319) — that is the authoritative Microsoft listing for the identifier. The MSRC entry is the place to watch for the vendor advisory, affected products list and patch notes. At the time of writing the page exists but the in‑page content is rendered dynamically by Microsoft’s web app; for full technical details users should consult the MSRC advisory page and any linked vendor advisories from Microsoft / GitHub / extension authors. (msrc.microsoft.com)
Context from recent, directly documented incidents
To understand CVE-2025-55319 you should view it in context of a cluster of agentic AI vulnerabilities disclosed in 2025:
- Claude Code command‑injection issues: public advisories and NVD listings document command parsing and confirmation bypass vulnerabilities in the Claude Code ecosystem in which attackers could bypass confirmation prompts and execute injected commands or exfiltrate files — fixed in newer library/extension releases. These incidents illustrate how “bypass the confirmation” and “write to workspace config” problems are practical for attackers. (nvd.nist.gov)
- Cursor editor vulnerabilities: Cursor and similar tools used an MCP (Model Control Protocol) config file that, if modified by an attacker via a prompt‑injection, could result in automatic execution of newly added entries. Researchers showed how a single poisoned message could cause silent writes and immediate execution. The report highlights that “auto‑run” or “auto‑approve” semantics are extraordinarily dangerous. (thehackernews.com)
- GitHub Copilot / VS Code RCE reporting: independent writeups and vendor advisories described prompt injection variants that manipulate workspace settings (for example, settings.json) to change agent behavior (e.g., auto‑approval flags), allowing an agent easier route to run commands. These narratives map directly to the conceptual attack chain that yields RCE. (cybersecuritynews.com)
How an attacker would chain this attack (technical overview)
Below is a generalized attack chain based on documented exploit patterns. Do not treat it as specific proof about CVE-2025-55319 — rather, it explains the mechanics security teams must defend against:
- Initial delivery (attacker controls content the agent will read)
- The attacker plants malicious instructions in a README, source file, issue tracker, web page or chat message that the developer’s agent will later fetch or process. This is the classic “prompt injection” vector. Academic work shows web agents are routinely susceptible to low‑effort injections when they process external web content. (arxiv.org)
- Prompt injection manipulates agent behavior
- The embedded instruction is crafted to relocate or rewrite a configuration fragment the agent can modify (for example, .vscode/settings.json, .roo/mcp.json, ~/.cursor/mcp.json, or other MCP configuration files). The injection persuades the agent to write a configuration line that grants more permissions (e.g., auto‑approve or auto‑run). This pattern maps to multiple public advisories. (thehackernews.com)
- Configuration change enables privileged operations
- With the setting flipped, the agent no longer requires human confirmation for certain actions. It can now write files, invoke shell commands, or add remote MCP servers which themselves can issue commands.
- Execution and persistence
- The agent writes a command or script to a workspace file (or instructs a configured MCP provider to run a command). That command executes under the user’s account — allowing arbitrary code execution, exfiltration, installation of persistence mechanisms, or lateral movement.
- Exfiltration and clean‑up
- The attacker sets up outbound channels (curl to a C2, or using preconfigured cloud API keys accidentally exposed in the workspace) to exfiltrate data, then removes traces by reverting workspace files or deleting logs.
- Many agents are designed for convenience: they read your repo, open files, and are expected to automate commands. That makes them powerful but also risky if they accept untrusted content as input. The attack complexity is often low if auto‑approve features are on or confirmation prompts are bypassable. Several vulnerabilities disclosed in 2025 exploited exactly these tradeoffs. (security.snyk.io)
- Who’s at risk: Developers using agentic extensions (in VS Code, JetBrains IDEs, etc.), CI runners that automatically run agents, and any user who opens untrusted repos or browses attacker‑controlled web content while an agent is active.
- Impact scope: Code execution under the user’s privileges — which means ransomware, credential theft, codebase tampering, and lateral movement in corporate networks are all realistic follow‑on effects. Past advisories show significant confidentiality and integrity impacts in similar CVEs. (nvd.nist.gov)
Apply this checklist as an urgent, short‑term response while waiting for vendor patches / detailed MSRC guidance:
- Update first
- Check MSRC’s CVE page and vendor advisories for patches and apply updates to Visual Studio Code, Visual Studio, and any agentic extensions (Claude Code, Cursor, Roo, Copilot extensions, etc.). The MSRC CVE page is the canonical place to start. (msrc.microsoft.com)
- Disable risky “auto‑approve / auto‑run” settings
- If your agent or extension has an “auto‑approve” or “auto‑run” toggle for tool invocations, turn it off. Prior incidents show this single setting is often the pivot that allows exploits. (thehackernews.com)
- Restrict workspace file writes
- Set workspace or repository policies that prevent extensions from writing to sensitive configuration locations (.vscode, ~/.config, .roo, ~/.cursor) without explicit, visible UI prompts. If the tool offers a mode that shows diffs instead of writing directly, enable that.
- Run agents in constrained environments
- When possible, run agent tooling in containers or VMs that have no persistent credentials and limited network access. For CI, avoid letting agents run with elevated or persisted secrets.
- Network egress controls
- Use egress filtering and DNS controls to block unexpected outbound connections from developer machines. If an exploit triggers, blocking egress makes data exfiltration and C2 callbacks harder.
- Least privilege on secrets
- Avoid storing long‑lived keys on developer workstations. Use short‑lived tokens and guarded secret stores so an agent with RCE can’t trivially pivot to cloud resources.
- Educate developers
- Warn teams not to open unknown repos, click links in untrusted READMEs, or ask agents to process content pulled from the web without manual review.
If you operate logging and detection, prioritize these signal sets:
- File system monitoring
- Alert on unexpected writes to workspace config files (.vscode/settings.json, project‑level MCP files like .roo/mcp.json, ~/.cursor/mcp.json). Many advisories name these files as attack pivots. (nvd.nist.gov)
- Process telemetry
- Watch for IDE processes spawning shells (powershell.exe, cmd.exe, bash, sh) from extension/agent processes. Correlate child processes to the IDE extension host.
- Network telemetry
- Alert on developer endpoints making outbound connections to suspicious domains or IPs shortly after editing/opening new projects — especially POSTs with likely exfiltrated content.
- Endpoint detections
- Watch for new persistence files or scheduled tasks being created from developer accounts after agent activity.
- Audit logs
- Track Git commits done from developer machines that are out of band (e.g., auto‑committed changes to settings.json). Suspicious diffs that add agent‑privilege lines (like "chat.tools.autoApprove": true) are immediate red flags. (cybersecuritynews.com)
The security community and researchers have repeatedly proposed and (in some cases) seen fixes that reduce systemic risk:
- Default to deny and require explicit, human‑visible confirmation for any action that writes privileged config or executes shell commands. Do not present the confirm dialog inside the agent conversation UI — use OS‑level prompts or show a diff in the IDE.
- Remove or heavily restrict “auto‑approve” semantics. If an allowlist model is needed, make it per‑project and require cryptographic consent for changes.
- Harden agent input handling: sanitize and strip hidden/unprintable characters that attackers use to hide prompt injections, and apply context‑aware sanitization so the model cannot treat repo content as executable instructions. Academic benchmarks (WASP, CVE‑Bench) show prompt injection remains a practical vector unless models and agents treat external content as untrusted. (arxiv.org)
- Improve developer observability: toolmakers should emit signed action logs for any automatically executed actions (who approved, what changed, timestamp) that can be audited.
- Security testing for agents: run red‑team prompt injection tests and include agentic workflows in vulnerability scans and CI security gates.
- Short term (hours): Disable agentic extensions on sensitive hosts and enforce egress filtering for developer machines.
- Short‑medium term (days): Roll out updates from VS Code / extension vendors when they’re published. Add file‑write auditing to EDR and alert on changes to workspace config files. Rotate any long‑lived developer credentials.
- Medium term (weeks): Move development workspaces into hardened containers with minimal host privileges. Create a policy to require code review before agents can be used on sensitive repos.
- Visit the MSRC CVE page you linked and check for vendor advisories or mitigations linked there. If a patch is available, prioritize it. (msrc.microsoft.com)
- If you run agentic plugins (Copilot, Claude Code, Cursor, Roo, etc.), check their security advisories and update them. Recent disclosures across those projects show the exact attack primitives being used. (nvd.nist.gov)
- If you are a sysadmin, push an organization‑wide guidance to developers: do not enable auto‑approve settings; avoid opening untrusted repos; and report any unexpected workspace file changes to security teams. (cybersecuritynews.com)
Vendors and CNAs often withhold exploit‑level technical details until patches exist to avoid catalyzing mass exploitation. That can result in a brief period where only the CVE identifier and a high‑level description are public — which is why the MSRC listing is the authoritative starting point and why defenders must act on posture changes rather than waiting for detailed PoC code. (msrc.microsoft.com)
Concluding note
CVE-2025-55319 sits squarely in a trend: agentic AI tooling increases developer productivity but also expands the attack surface in new ways. The concrete lessons from Claude Code, Cursor, Copilot and other advisories are clear: never give agents unchecked authority to modify security‑relevant configuration or execute shell commands without robust, human‑visible confirmations and strong defaults. Patch swiftly, remove auto‑approve behavior, and monitor the signals outlined above until vendor patches and improved designs are widely deployed. (nvd.nist.gov)
Selected references and reading
- Microsoft Security Update Guide — CVE-2025-55319 (vendor entry / canonical listing). (msrc.microsoft.com)
- NVD & GitHub advisory coverage for Claude Code command injection (examples of agentic RCE patterns). (nvd.nist.gov)
- The Hacker News: Cursor AI editor prompt‑injection / MCP issues and mitigation steps. (thehackernews.com)
- Industry writeups about Visual Studio / Copilot prompt injection & RCE patterns. (cybersecuritynews.com)
- WASP (academic benchmark) on web agent prompt injection attacks. (arxiv.org)
- I can: (a) monitor MSRC and vendor advisory pages and notify you when Microsoft publishes a full advisory or patch notes for CVE‑2025‑55319, (b) produce a tight, copy‑pasteable checklist you can circulate to your dev teams and SOC, or (c) help craft a hunting query (SIEM/EDR) for the specific artifacts described above (settings.json changes, child shell spawns, specific MCP file edits). Which would you like me to do next?
Source: MSRC Security Update Guide - Microsoft Security Response Center