CVE-2016-20063: SQL Injection in Single Personal Message 1.0.3 – Credential & Data Theft Risk

Technical summary

This is a classic SQL injection vulnerability (CWE-89) in the message parameter handling of Single Personal Message 1.0.3. The vulnerability requires prior authentication—an attacker must have valid user credentials to access the message functionality. Once authenticated, unsanitized input is passed directly into SQL queries without proper parameterization or escaping. The attack surface is the admin interface or message submission endpoints, where an attacker can inject SQL fragments to alter query logic and extract, modify, or delete data. The CVSS 3.1 score of 7.1 (HIGH) reflects high confidentiality impact, limited integrity risk, and no availability impact, with a low attack complexity and network-accessible vector.

Business impact

Compromise of user credentials and site configuration data poses significant operational and compliance risk. Attackers gaining access to credential hashes or plaintext passwords can escalate privileges, move laterally to other systems, or launch credential stuffing attacks. Exposure of site configuration may reveal API keys, database connection strings, or other secrets used in the wider infrastructure. For organizations running Single Personal Message as a messaging or collaboration plugin, this creates a persistent insider-threat vector: any compromised user account becomes a pivot point for data exfiltration.

Affected systems

Single Personal Message version 1.0.3 is affected. No patch version information is provided in the source data; organizations running this version should verify against the vendor advisory for available updates or workarounds.

Exploitability

Exploitability is moderate to high in practice. While the vulnerability requires prior authentication (reducing random attack surface), compromised user accounts, insider threats, or weak default credentials are common entry points. Once authenticated, crafting SQL injection payloads is straightforward for an attacker with basic SQL knowledge. No public exploit code or KEV (Known Exploited Vulnerability) status is currently documented, but the simplicity of SQL injection attacks means exploitation could occur quickly if the vulnerability becomes public knowledge.

Remediation

Immediate action: upgrade Single Personal Message to a patched version confirmed by the vendor to address CWE-89 SQL injection. Interim mitigations include: (1) restrict access to the admin interface and message functionality to trusted IP ranges or VPN; (2) implement strict input validation and length limits on the message parameter; (3) use parameterized queries or prepared statements in code (if source access is available); (4) enable database-level query logging to detect suspicious SQL patterns; (5) review user account access and revoke unnecessary administrative privileges.

Patch guidance

Consult the Single Personal Message vendor advisory for available patches. Apply patches to all instances of version 1.0.3 in your environment. If a patched version exists, prioritize testing and deployment within your change management window. If no patch is available, escalate to the vendor for a timeline and implement the interim mitigations listed above.

Detection guidance

Monitor application logs and database query logs for: (1) SQL syntax errors or unusual SQL statements in the message parameter; (2) attempts to access information_schema or system tables; (3) UNION SELECT, OR 1=1, or other common SQL injection payloads in message submissions; (4) database queries executed by the application user with unexpected complexity or access patterns. Implement Web Application Firewall (WAF) rules to block common SQL injection signatures. Enable query auditing on the backend database to flag queries that deviate from expected patterns.

Why prioritize this

This vulnerability warrants HIGH priority due to its direct impact on data confidentiality (user credentials and configuration secrets), the ease of exploitation once authenticated, and the potential for lateral movement or privilege escalation. Although authentication is required, the abundance of compromised or weak user credentials in most organizations makes this a realistic attack path. The lack of KEV status suggests it is not yet actively exploited at scale, but prompt patching will close the window before adversaries weaponize it.

Risk score, explained

The CVSS 3.1 score of 7.1 (HIGH) reflects: high confidentiality impact (an attacker can extract sensitive data such as credentials), low integrity impact (the vulnerability allows modification of data but is not the primary attack vector), and no availability impact (the attacker cannot cause denial of service). The attack requires authentication (PR:L) and is network-accessible (AV:N) with low complexity (AC:L), making it a practical threat in real deployments. The score appropriately elevates this from MEDIUM to HIGH due to the sensitivity of exfiltrated data.

Frequently asked questions