CVE-2025-67818: 
NixOS vulnerability analysis and mitigation

CVE-2025-67818 is a path traversal (ZipSlip) vulnerability in Weaviate OSS, an open-source vector database, that allows an attacker with database insertion privileges to escape the backup restore root directory and create or overwrite files in arbitrary locations within the application's privilege scope. It was published on December 12, 2025, and affects Weaviate OSS versions before 1.30.20, 1.31.0-rc.0 through 1.31.19, 1.32.0-rc.0 through 1.32.16, and 1.33.0-rc.0 through 1.33.4. The vulnerability carries a CVSS v3.1 base score of 7.2 (High) and a CVSS v4 base score of 8.7 (High) (Github Advisory, Feedly).

The vulnerability is classified as CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-61 (UNIX Symbolic Link Following), representing a classic ZipSlip attack pattern during backup restoration (Github Advisory). An attacker with write access to the Weaviate database can insert an entry whose name contains an absolute path (e.g., /etc/cron.d/malicious) or parent directory traversal sequences (e.g., ../../sensitive_location) into the database. When a backup containing this crafted entry is subsequently restored, Weaviate fails to sanitize or validate the entry name against the intended restore root directory, causing files to be written outside the designated backup restoration path. The fix is tracked in commits 169df2d and 89c2270 in the Weaviate repository (Github Advisory).

Successful exploitation allows an attacker to create or overwrite arbitrary files anywhere within the filesystem locations accessible to the Weaviate process. This can lead to compromise of system integrity (e.g., overwriting configuration files, cron jobs, or application binaries), potential code execution if writable locations such as cron directories or startup scripts are targeted, and exposure of sensitive data if critical system files are replaced. The confidentiality, integrity, and availability of the host system are all at risk, with the blast radius limited by the privileges of the Weaviate service account (Github Advisory, Feedly).

There is no public proof-of-concept exploit code and no evidence of active in-the-wild exploitation at this time (Feedly). Exploitation requires high-privileged access (the ability to insert data into the Weaviate database) and a subsequent backup restore operation, which limits opportunistic exploitation. The EPSS score is approximately 0.21–0.34%, placing it in the 44th percentile for exploitation likelihood within 30 days (Github Advisory). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, and no threat actor attribution has been reported.

1. Gain database insertion access: Obtain credentials or API access with write privileges to a vulnerable Weaviate OSS instance (versions before 1.30.20, 1.31.19, 1.32.16, or 1.33.4).
2. Craft a malicious entry: Insert a database object or backup entry whose name contains a path traversal sequence, such as ../../etc/cron.d/backdoor or an absolute path like /etc/cron.d/backdoor, using the Weaviate REST, gRPC, or GraphQL API.
3. Trigger a backup: Initiate a backup of the Weaviate database that includes the maliciously named entry, using the Weaviate backup API endpoint.
4. Trigger a restore: Initiate a restore operation from the crafted backup. Weaviate processes the entry names without sufficient path sanitization, causing the file to be written to the traversal-resolved location (e.g., /etc/cron.d/backdoor) rather than within the restore root.
5. Achieve objective: The written file (e.g., a cron job, web shell, or configuration override) executes under the Weaviate service account's privileges, potentially enabling persistent access or further lateral movement (Github Advisory).

• File System: Unexpected files created outside the Weaviate data/backup directory, particularly in sensitive locations such as /etc/cron.d/, /etc/cron.hourly/, /tmp/, or application configuration directories; files with timestamps matching backup restore operations.
• Logs: Weaviate application logs showing restore operations with entry names containing ../, ..\, or absolute paths (e.g., /etc/); errors or warnings during backup restore related to file path resolution.
• Process: Unusual processes spawned by the Weaviate service account (e.g., shell processes, network connections) following a backup restore event.
• Network: Unexpected outbound connections from the Weaviate host following a restore operation, which may indicate post-exploitation activity such as reverse shell establishment.

Weaviate has released patched versions addressing this vulnerability: 1.30.20, 1.31.19, 1.32.16, and 1.33.4. All users should upgrade to the appropriate patched version for their release branch as the primary remediation (Github Advisory, Weaviate Blog). As interim mitigations, restrict database insertion privileges to only trusted users, apply the principle of least privilege to the Weaviate service account to limit the filesystem locations it can write to, and avoid performing backup restore operations from untrusted or externally sourced backups.

Weaviate published a security release blog post in November 2025 addressing this and potentially other vulnerabilities (Weaviate Blog). The vulnerability was noted on Bluesky by CVE tracking accounts and covered by security aggregators including InfinitSec, VulnDB, and INCIBE-CERT shortly after disclosure (Feedly). No significant broader media coverage or notable researcher commentary beyond standard vulnerability tracking has been identified.