CVE-2026-25606: STER SQL Injection Vulnerability

CVE-2026-25606 Overview

CVE-2026-25606 is a SQL injection vulnerability affecting the STER application. The flaw stems from improper neutralization of user-supplied input passed into multiple search filters. An authenticated attacker can inject SQL payloads through these filter parameters and retrieve sensitive data accessible to the application database account. This includes records belonging to other users and any other data the application backend can query. The vendor addressed the issue in STER version 9.5. The vulnerability is tracked under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact

An authenticated attacker can extract sensitive data from the STER database by injecting SQL through multiple search filter inputs, exposing records belonging to other users.

Affected Products

• STER application versions prior to 9.5
• Search filter components within STER that process user-supplied input
• Database backend accessed by the STER application

Discovery Timeline

• 2026-05-22 - CVE-2026-25606 published to the National Vulnerability Database
• 2026-05-22 - Last updated in NVD database
• 2026-05-28 - EPSS scoring data published

Technical Details for CVE-2026-25606

Vulnerability Analysis

The vulnerability resides in STER's handling of search filter parameters. The application accepts user input through multiple search filters and concatenates that input into SQL queries without proper neutralization or parameterization. An authenticated user with access to the search functionality can craft input that alters the structure of the resulting SQL statement.

Successful exploitation allows an attacker to read data outside of their authorization scope. This includes records owned by other users and any other tables the application's database role can query. The impact is constrained to confidentiality and integrity at the application data layer, with limited effect on availability.

Because the attack vector is network-based and only requires low-privilege authentication, any user account with access to the affected search interfaces can perform exploitation. No user interaction beyond submitting crafted filter values is required.

Root Cause

The root cause is improper neutralization of special characters in user-controlled input incorporated into SQL queries [CWE-89]. The STER search filter handlers do not use prepared statements or parameterized queries, and they fail to sanitize input before query construction. This allows attacker-controlled syntax to be interpreted as part of the SQL command rather than as literal data.

Attack Vector

The attacker authenticates to the STER application using valid low-privilege credentials. The attacker then submits crafted payloads through one or more vulnerable search filter parameters. The injected SQL alters the query logic, enabling extraction of data the attacker is not authorized to access. Standard SQL injection techniques such as UNION-based extraction, boolean-based blind injection, and time-based blind injection are applicable to vulnerable endpoints that concatenate filter values into queries. Additional technical detail is available in the CERT Polska advisory for CVE-2026-25606.

Detection Methods for CVE-2026-25606

Indicators of Compromise

• Search filter requests containing SQL meta-characters such as single quotes, double dashes, UNION, SELECT, OR 1=1, or comment sequences
• Database query logs showing unusually long or malformed queries originating from search filter handlers
• Application errors referencing SQL syntax issues correlated with authenticated user sessions
• Unexpected data access patterns where a single authenticated account reads large volumes of records belonging to other users

Detection Strategies

• Enable verbose query logging on the STER database backend and review queries originating from search filter endpoints for anomalous structure
• Deploy a web application firewall with SQL injection signatures applied to STER search filter request parameters
• Correlate authentication logs with database access volumes to identify accounts performing unusual cross-user data reads
• Inspect HTTP request bodies and query strings for SQL grammar tokens submitted to STER filter parameters

Monitoring Recommendations

• Alert on repeated SQL syntax errors generated by the STER application within short time windows
• Monitor for authenticated sessions issuing high-volume read operations against tables containing user-scoped data
• Track requests to STER search endpoints that include URL-encoded SQL keywords or escape sequences
• Review audit logs for access to records outside the authenticated user's normal scope

How to Mitigate CVE-2026-25606

Immediate Actions Required

• Upgrade STER to version 9.5 or later, which contains the official fix for this vulnerability
• Review database query logs for evidence of prior exploitation attempts using SQL meta-characters in search filters
• Audit user accounts and rotate credentials for any account suspected of exploitation activity
• Restrict access to STER search functionality to the minimum set of users required for business operations

Patch Information

The vendor fixed the SQL injection vulnerability in STER version 9.5. Organizations running earlier versions must upgrade to receive the fix. Refer to the CERT Polska advisory and the CIOP product resource for vendor guidance.

Workarounds

• Deploy a web application firewall rule set that blocks SQL injection payloads targeting STER search filter parameters until patching is complete
• Apply least-privilege principles to the database account used by STER, restricting it to only the tables and operations required
• Disable or restrict access to vulnerable search filter functionality where business processes permit
• Enforce strict input validation at a reverse proxy layer to reject filter values containing SQL meta-characters

# Example WAF rule (ModSecurity) to block common SQLi patterns on STER search endpoints
SecRule REQUEST_URI "@beginsWith /ster/search" \
    "id:1002601,phase:2,deny,status:403,\
    chain,msg:'Potential SQL Injection in STER search filter'"
    SecRule ARGS "@rx (?i)(union(\s|/\*.*\*/)+select|or\s+1=1|--|;--|/\*|\*/|xp_cmdshell)"