CVE-2026-11347 Overview
The linqi application contains hardcoded cryptographic keys embedded in its codebase. The application compounds this weakness by deriving Initialization Vectors (IVs) for AES Cipher Block Chaining (AES/CBC) encryption from a limited ASCII character set using a weak algorithm. This design enables known-plaintext attacks against encrypted data. An attacker with local access can decrypt obfuscated strings, including ConnectionString values containing database credentials stored in appsettings.json. The flaw is tracked under CWE-321: Use of Hard-coded Cryptographic Key.
Critical Impact
Local attackers can recover plaintext database credentials and other secrets protected by linqi's cryptographic routines, leading to full compromise of backend data stores.
Affected Products
- linqi application (see vendor advisory for affected versions)
Discovery Timeline
- 2026-06-05 - CVE-2026-11347 published to NVD
- 2026-06-05 - Last updated in NVD database
Technical Details for CVE-2026-11347
Vulnerability Analysis
The linqi application implements a custom string obfuscation layer built on AES/CBC. Two design flaws undermine the scheme. First, the symmetric encryption key is hardcoded in the application binaries and is identical across deployments. Second, the routine that produces per-message IVs draws values from a restricted printable ASCII character set rather than a cryptographically secure random source.
Both weaknesses break the confidentiality guarantees of AES/CBC. A reduced IV entropy space combined with a static key allows an attacker to mount known-plaintext attacks. Once the key and IV generation algorithm are recovered through binary analysis, every encrypted blob across every linqi installation becomes decryptable.
The practical target is appsettings.json, where linqi stores obfuscated ConnectionString values. Recovering these strings yields direct database credentials, exposing customer records, configuration data, and any secrets the database holds.
Root Cause
The root cause is twofold: storage of a long-lived symmetric key inside distributed application artifacts, and use of a non-cryptographic IV generator constrained to ASCII characters. Cryptographic primitives such as AES/CBC require unique, unpredictable IVs and externally protected keys to remain secure.
Attack Vector
Exploitation requires local access with low privileges on a host running linqi. An attacker reads the obfuscated configuration values from disk, extracts the hardcoded key from the application binaries, and applies the documented IV derivation routine to decrypt the ciphertext. No user interaction is required. Refer to the Linqi Security Advisory on Cryptography for vendor-supplied technical detail.
Detection Methods for CVE-2026-11347
Indicators of Compromise
- Unauthorized reads of appsettings.json or other linqi configuration files by non-service accounts.
- Outbound database connections from hosts or IP ranges that do not normally communicate with the linqi database tier.
- Presence of decryption tooling, debuggers, or binary analysis utilities on production application servers.
Detection Strategies
- Monitor file access auditing on linqi installation directories and flag access by interactive user sessions.
- Correlate database authentication events with originating process and host to identify use of credentials outside the linqi application process.
- Alert on copies of linqi configuration files leaving the host through file shares, cloud sync, or removable media.
Monitoring Recommendations
- Enable Windows or Linux file integrity monitoring on appsettings.json and adjacent configuration files.
- Forward authentication logs from the backing database to a central SIEM and baseline expected client identities.
- Track local logon events on linqi hosts and review accounts with read access to application directories.
How to Mitigate CVE-2026-11347
Immediate Actions Required
- Apply the patched linqi release identified in the Linqi Security Advisory on Cryptography.
- Rotate every database credential and secret previously stored in appsettings.json on linqi hosts.
- Restrict filesystem permissions on linqi configuration files to the service account only.
- Review database audit logs for unexpected logons that may indicate prior credential recovery.
Patch Information
The vendor has published a security advisory documenting the hardcoded key and weak IV generation issues, along with fixed releases. Consult the Linqi Security Advisory on Cryptography for version-specific guidance.
Workarounds
- Move sensitive ConnectionString values out of appsettings.json into an external secret store such as a managed key vault.
- Apply operating system access control lists that block non-service accounts from reading linqi application directories.
- Isolate linqi hosts on a dedicated network segment and limit interactive logons to administrators.
# Example: restrict appsettings.json to the linqi service account on Linux
chown linqi:linqi /opt/linqi/appsettings.json
chmod 600 /opt/linqi/appsettings.json
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
