ShadowLeak and ZombieAgent: Critical ChatGPT Flaws Enable Zero-Click Data Exfiltration from Gmail, Outlook, and GitHub

Understanding the ShadowLeak Vulnerability

ShadowLeak exploited a critical flaw in ChatGPT's Connector architecture—the feature that allows ChatGPT to access external services like Gmail, Outlook, and GitHub on behalf of users. The vulnerability enabled attackers to craft malicious prompts that would:

1. Bypass authorization checks on connected services
2. Silently query user data without triggering security alerts
3. Exfiltrate information through ChatGPT's response generation

Attack Vector Analysis

The attack required no user interaction beyond the initial connection setup. Once a user had linked their accounts to ChatGPT, an attacker could exploit the vulnerability by:

• Embedding malicious instructions in seemingly benign content
• Leveraging ChatGPT's context window to maintain persistent access
• Using the AI's summarization capabilities to extract and transmit data

ZombieAgent: Self-Propagating Memory Attacks

The ZombieAgent vulnerability represents an even more sophisticated threat vector. By exploiting ChatGPT's persistent Memory feature, attackers could:

Infection Chain

Stage	Action	Impact
Initial Compromise	Malicious prompt injection	Memory poisoned
Persistence	Instructions stored in Memory	Survives logout
Propagation	Spreads to new conversations	Self-replicating
Exfiltration	Data sent to attacker	Continuous theft

The self-propagating nature meant that once infected, a ChatGPT instance would automatically attempt to compromise other connected services and conversations.

Technical Deep Dive: Connector Architecture Flaws

OAuth Token Handling

ChatGPT Connectors use OAuth 2.0 to access third-party services. The vulnerability stemmed from insufficient validation of:

• Scope boundaries: The AI could request data beyond user-authorized scopes
• Token refresh flows: Malicious prompts could trigger unauthorized token refreshes
• Cross-service contamination: Data from one service could leak to another

Attack Flow:
User connects Gmail → Attacker crafts prompt → 
ChatGPT queries Gmail API → Data returned in response →
Attacker extracts via conversation

Memory Persistence Exploitation

The Memory feature stores information in a vector database without adequate sanitization:

1. Attacker injects payload disguised as user preference
2. Memory stores malicious instruction
3. Future conversations execute stored payload
4. Attack persists indefinitely

Affected Services and Data Types

The vulnerabilities impacted all ChatGPT Connectors, with confirmed exploitation vectors for:

Gmail Integration

• Email content and attachments
• Contact lists and addresses
• Calendar events and scheduling data
• Draft messages

Microsoft Outlook

• Corporate email correspondence
• Meeting invitations
• Shared document links
• Organization directory data

GitHub

• Repository contents (including private repos)
• Issue discussions and comments
• Pull request details
• API keys in configuration files

OpenAI's Response and Remediation

OpenAI responded within 48 hours of responsible disclosure:

Immediate Actions

• Connector isolation: Implemented stricter sandboxing between services
• Memory sanitization: Added input validation for Memory writes
• Token scope restrictions: Limited OAuth permissions to exact requirements

Long-term Fixes

• Deployed anomaly detection for unusual data access patterns
• Implemented rate limiting on Connector API calls
• Added user notifications for suspicious Memory modifications

Implications for AI Security

Zero-Click Attack Evolution

ShadowLeak and ZombieAgent represent a new category of AI-specific vulnerabilities:

1. No phishing required: Attacks work through legitimate platform features
2. Invisible to users: No suspicious links or attachments
3. Self-sustaining: Memory persistence enables long-term compromise
4. Cross-platform: Single vulnerability affects multiple connected services

Enterprise Security Recommendations

Priority	Action	Implementation
Critical	Audit Connector permissions	Review all linked services
High	Enable Memory notifications	Alert on Memory changes
High	Implement data loss prevention	Monitor AI-generated content
Medium	Regular token rotation	Force re-authentication
Medium	Network segmentation	Isolate AI service access

Protecting Your Organization

Immediate Steps

1. Review connected services: Audit which services are linked to ChatGPT
2. Clear Memory data: Remove potentially compromised stored information
3. Rotate credentials: Change passwords and API keys for connected accounts
4. Enable logging: Monitor ChatGPT API access patterns

Policy Recommendations

Organizations should establish clear policies for:

• AI tool authorization: Require security review before Connector activation
• Data classification: Prevent sensitive data from flowing through AI services
• Incident response: Include AI compromise scenarios in security playbooks
• User training: Educate employees on AI-specific phishing vectors