CVE-2024-7340: Weave Server Path Traversal Vulnerability

CVE-2024-7340 Overview

CVE-2024-7340 is a path traversal vulnerability in the Weave server API that allows remote users to fetch files from a specific directory. Due to a lack of input validation, attackers can traverse directory structures and leak arbitrary files remotely. In various common scenarios, this allows a low-privileged user to assume the role of the server admin, significantly escalating their privileges within the system.

Critical Impact
Remote attackers with low-level access can exploit this path traversal flaw to read sensitive files and potentially escalate privileges to server administrator level.

Affected Products

Weave Server (Weights & Biases)
wandb/weave package versions prior to patch

Discovery Timeline

2024-07-31 - CVE-2024-7340 published to NVD
2024-11-25 - Last updated in NVD database

Technical Details for CVE-2024-7340

Vulnerability Analysis

This vulnerability stems from insufficient input validation in the Weave server API's file retrieval functionality. The API is designed to allow remote users to fetch files from a designated directory, but fails to properly sanitize user-supplied input for path traversal sequences such as ../. This improper input validation (CWE-20) combined with the path traversal weakness (CWE-22) enables attackers to escape the intended directory constraints and access arbitrary files on the server filesystem.

The network-accessible nature of this vulnerability means that any authenticated user with low-level privileges can potentially exploit it without requiring any user interaction. The successful exploitation results in high impact to confidentiality, integrity, and availability, as sensitive configuration files, credentials, and system data may be exposed, potentially allowing the attacker to assume administrative control of the server.

Root Cause

The root cause is improper input validation (CWE-20) combined with path traversal (CWE-22) in the file retrieval functionality. The Weave server API does not adequately sanitize file path parameters, allowing directory traversal sequences to bypass intended access restrictions. When processing file requests, the application concatenates user-supplied input directly into file system paths without validating that the resulting path stays within the allowed directory boundary.

Attack Vector

The attack is executed over the network by an authenticated user with minimal privileges. An attacker sends crafted API requests containing path traversal sequences (e.g., ../../../etc/passwd or similar patterns) to the file retrieval endpoint. Since the server fails to validate and normalize the requested path, it follows the traversal sequences and returns files outside the designated directory.

The exploitation chain typically involves:

Authenticating to the Weave server with a low-privilege account
Identifying the vulnerable file retrieval API endpoint
Crafting malicious requests with path traversal payloads
Retrieving sensitive files such as configuration files, API keys, or authentication tokens
Using obtained credentials or secrets to escalate privileges to server administrator

For technical details on the vulnerability mechanism, refer to the JFrog Vulnerability Report.

Detection Methods for CVE-2024-7340

Indicators of Compromise

Unusual file access patterns in server logs, particularly requests containing ../ sequences
API requests targeting paths outside the expected directory structure
Unexpected access to sensitive system files like /etc/passwd, configuration files, or credential stores
Authentication anomalies or privilege escalation events following file access attempts

Detection Strategies

Monitor web server and application logs for path traversal patterns including ../, ..\, %2e%2e%2f, and URL-encoded variants
Implement Web Application Firewall (WAF) rules to detect and block path traversal attempts in API requests
Deploy file integrity monitoring on sensitive directories to detect unauthorized read access
Utilize SentinelOne Singularity XDR to detect suspicious file access patterns and potential exploitation activity

Monitoring Recommendations

Enable verbose logging on the Weave server API to capture detailed request information
Configure alerts for any file access outside designated directories
Monitor for sudden changes in user privilege levels that may indicate successful exploitation
Review authentication logs for anomalous login patterns following potential exploitation attempts

How to Mitigate CVE-2024-7340

Immediate Actions Required

Update Weave server to the latest patched version immediately
Review access logs for signs of exploitation attempts or successful attacks
Audit user accounts for any unauthorized privilege escalations
Implement network segmentation to limit exposure of the Weave server API
Rotate any credentials or API keys that may have been exposed

Patch Information

The vulnerability has been addressed by the Weights & Biases team. The fix is available in the GitHub Pull Request #1657. Organizations should update their Weave server installation to incorporate this security patch. Review the JFrog Vulnerability Report for additional technical details and remediation guidance.

Workarounds

Implement strict input validation at the network perimeter using WAF rules to block path traversal patterns
Restrict network access to the Weave server API to trusted IP ranges only
Run the Weave server in a containerized environment with limited filesystem access
Apply principle of least privilege to the Weave server process, limiting its ability to read sensitive system files

bash

# Example WAF rule to block path traversal attempts
# Add to your reverse proxy or WAF configuration
SecRule REQUEST_URI "@rx \.\./" "id:1001,phase:1,deny,status:403,msg:'Path Traversal Attempt'"
SecRule REQUEST_URI "@rx %2e%2e%2f" "id:1002,phase:1,deny,status:403,msg:'Encoded Path Traversal Attempt'"