CVE-2026-51821 Overview
CVE-2026-51821 is a SQL Injection vulnerability in Shenzhou Shihan Video Conference System v1.0. The flaw resides in the /user/getUserLogin endpoint, which fails to sanitize user-supplied input before incorporating it into SQL statements. A remote, unauthenticated attacker can inject arbitrary SQL queries and, per the advisory, execute arbitrary code against the underlying system. The weakness is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.
Critical Impact
Unauthenticated remote attackers can inject SQL through the login endpoint, leading to database compromise and arbitrary code execution on the Shenzhou Shihan Video Conference System v1.0.
Affected Products
- Shenzhou Shihan Video Conference System v1.0
- Deployments exposing the /user/getUserLogin endpoint to untrusted networks
- Backend database instances tied to the vulnerable web application
Discovery Timeline
- 2026-07-13 - CVE-2026-51821 published to the National Vulnerability Database (NVD)
- 2026-07-15 - Last updated in NVD database
Technical Details for CVE-2026-51821
Vulnerability Analysis
The vulnerability affects the login handler exposed at /user/getUserLogin in the Shenzhou Shihan Video Conference System. Attacker-controlled parameters submitted to this endpoint are concatenated directly into a SQL query. Because the application does not use parameterized queries or input validation, the database engine parses attacker input as query logic.
Exploitation requires no authentication and no user interaction. An attacker with network access to the web interface can retrieve, modify, or delete arbitrary database records. According to the advisory, the flaw further enables arbitrary code execution, likely through database-layer primitives such as stacked queries, INTO OUTFILE writes, or stored procedure abuse depending on the database backend.
The current EPSS probability is 0.527%, placing the vulnerability in the 41st percentile for near-term exploitation likelihood. No public proof-of-concept exploit is currently listed in Exploit-DB, and the CVE is not on the CISA Known Exploited Vulnerabilities catalog.
Root Cause
The root cause is improper neutralization of special SQL characters in parameters accepted by /user/getUserLogin. The handler builds queries through string concatenation rather than prepared statements, permitting query structure alteration. Login endpoints commonly evaluate injected payloads before authentication checks complete, which is why unauthenticated exploitation is possible.
Attack Vector
The attack vector is network-based. An attacker sends a crafted HTTP request to /user/getUserLogin with SQL metacharacters embedded in a login parameter. The backend executes the tampered query, returning attacker-controlled data or performing writes. Refer to the GitHub issue for CVE-2026-51821 and the Cnblogs technical analysis for endpoint request details.
No verified proof-of-concept code is included here. See the linked external references for request structure and payload composition.
Detection Methods for CVE-2026-51821
Indicators of Compromise
- HTTP POST or GET requests to /user/getUserLogin containing SQL metacharacters such as ', --, UNION SELECT, SLEEP(, or OR 1=1
- Database error responses returned to unauthenticated clients from the login endpoint
- Anomalous outbound connections or unexpected file writes originating from the video conference application service account
- New or modified rows in authentication tables that do not correspond to legitimate account activity
Detection Strategies
- Deploy web application firewall (WAF) rules that inspect the /user/getUserLogin parameters for SQL injection signatures
- Correlate web access logs with database audit logs to identify malformed queries reaching the backend
- Alert on repeated login-endpoint requests from a single source that produce HTTP 500 errors or unusually large response bodies
Monitoring Recommendations
- Enable full HTTP request logging on the video conference application, including POST bodies where policy permits
- Turn on database query logging and forward logs to a central SIEM for pattern analysis
- Monitor for creation of unexpected OS-level files or scheduled tasks by the database service account, which may indicate post-exploitation activity
How to Mitigate CVE-2026-51821
Immediate Actions Required
- Restrict network access to the Shenzhou Shihan Video Conference System v1.0 web interface using firewall rules or VPN gating
- Place a WAF in front of the application with rules blocking SQL injection patterns against /user/getUserLogin
- Audit database accounts used by the application and remove unnecessary privileges such as FILE, EXECUTE, or DBA roles
- Review application, web server, and database logs for prior exploitation attempts against the affected endpoint
Patch Information
No vendor patch has been published in the referenced advisories at the time of writing. Consult the GitHub issue for CVE-2026-51821 and the Cnblogs analysis for updates. Contact Shenzhou Shihan directly to confirm remediation availability for v1.0 deployments.
Workarounds
- Block external access to /user/getUserLogin at the reverse proxy until a vendor fix is available
- Deploy virtual patching via WAF signatures that reject requests containing SQL metacharacters in login parameters
- Isolate the database server on a segmented network with strict egress filtering to limit post-exploitation impact
- Rotate application database credentials and any secrets that may have been exposed through the vulnerable endpoint
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
