CVE-2024-20417: Cisco Identity Services Engine SQLi Flaw

CVE-2024-20417 Overview

Multiple vulnerabilities in the REST API of Cisco Identity Services Engine (ISE) allow an authenticated, remote attacker to conduct blind SQL injection attacks. These vulnerabilities arise from insufficient validation of user-supplied input in REST API calls, enabling attackers to craft malicious input that could view or modify sensitive data on affected devices.

Cisco ISE is a critical network access control (NAC) solution used by organizations to enforce security policies, manage device access, and provide centralized authentication services. Compromise of this infrastructure component could have significant implications for enterprise network security posture.

Critical Impact

Authenticated attackers can exploit these SQL injection vulnerabilities to view or modify data on affected Cisco ISE deployments, potentially compromising network access control policies and sensitive authentication data.

Affected Products

• Cisco Identity Services Engine 3.1.0 (including patches 1-9)
• Cisco Identity Services Engine 3.2.0 (including patches 1-6)
• Cisco Identity Services Engine 3.3.0 (including patches 1-3)

Discovery Timeline

• August 21, 2024 - CVE-2024-20417 published to NVD
• March 31, 2025 - Last updated in NVD database

Technical Details for CVE-2024-20417

Vulnerability Analysis

CVE-2024-20417 represents a blind SQL injection vulnerability class (CWE-89) affecting the REST API endpoints of Cisco Identity Services Engine. The vulnerability allows authenticated attackers to inject malicious SQL statements through API requests, which are then executed by the underlying database without proper sanitization.

Blind SQL injection differs from traditional SQL injection in that the attacker cannot directly see the results of their queries. Instead, they must infer information based on the application's response behavior, timing differences, or conditional responses. This makes exploitation more complex but still highly dangerous, as attackers can systematically extract sensitive data or modify database contents.

The authentication requirement (low privileges needed) provides a minimal barrier to exploitation, as any user with valid API credentials could potentially leverage these vulnerabilities. Given that Cisco ISE manages network access policies and authentication data, successful exploitation could compromise the integrity of enterprise access control mechanisms.

Root Cause

The root cause of these vulnerabilities is insufficient validation and sanitization of user-supplied input within the REST API call handlers. When API requests are processed, user-controllable parameters are incorporated into SQL queries without proper parameterization or input validation, allowing attackers to inject arbitrary SQL syntax that alters the intended query logic.

This represents a failure to implement secure coding practices such as prepared statements, parameterized queries, or comprehensive input validation at the API layer. The REST API endpoints likely concatenate user input directly into SQL statements, creating injection points that attackers can leverage.

Attack Vector

The attack vector is network-based, requiring authenticated access to the Cisco ISE REST API. An attacker with valid credentials can send specially crafted API requests containing SQL injection payloads. The exploitation flow typically involves:

1. Authentication to the Cisco ISE REST API using valid credentials
2. Identification of vulnerable API endpoints that accept user input
3. Crafting malicious requests with SQL injection payloads in susceptible parameters
4. Using blind SQL injection techniques (time-based or boolean-based) to extract or modify data
5. Iteratively querying the database to map schema and extract sensitive information

Since no verified proof-of-concept code is publicly available for this vulnerability, organizations should refer to the Cisco Security Advisory for detailed technical guidance on affected endpoints and remediation steps.

Detection Methods for CVE-2024-20417

Indicators of Compromise

• Unusual or malformed REST API requests to Cisco ISE endpoints containing SQL syntax patterns such as UNION SELECT, WAITFOR DELAY, BENCHMARK, or SLEEP functions
• Abnormal API response times that may indicate time-based blind SQL injection attempts
• Multiple failed or anomalous API requests from a single authenticated user within short time periods
• Database query logs showing unexpected queries or error patterns from the ISE application

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns in API traffic
• Enable detailed logging on Cisco ISE REST API endpoints to capture request parameters and identify suspicious input patterns
• Deploy database activity monitoring to detect anomalous queries originating from the ISE application
• Configure SIEM correlation rules to alert on patterns indicative of blind SQL injection enumeration

Monitoring Recommendations

• Monitor Cisco ISE API access logs for requests containing SQL metacharacters, encoded payloads, or unusually long parameter values
• Track authentication events and correlate with subsequent API activity to identify potential account compromise leading to exploitation
• Establish baseline API usage patterns and alert on statistical deviations that may indicate automated exploitation attempts

How to Mitigate CVE-2024-20417

Immediate Actions Required

• Apply the security patches referenced in the Cisco Security Advisory immediately for all affected versions
• Review and restrict access to Cisco ISE REST API endpoints to only necessary personnel and systems
• Audit existing API user accounts and revoke any unnecessary or suspicious credentials
• Implement network segmentation to limit exposure of the ISE management interface

Patch Information

Cisco has released security patches to address these vulnerabilities. Organizations running affected versions should upgrade to patched releases as specified in the official Cisco Security Advisory. The advisory identifier is cisco-sa-ise-rest-5bPKrNtZ.

Affected versions requiring patching include:

• Cisco ISE 3.1.0 through 3.1.0 patch 9
• Cisco ISE 3.2.0 through 3.2.0 patch 6
• Cisco ISE 3.3.0 through 3.3.0 patch 3

Workarounds

• Restrict network access to Cisco ISE REST API endpoints using firewall rules or access control lists (ACLs)
• Implement additional authentication controls such as multi-factor authentication for API access
• Deploy a Web Application Firewall (WAF) with SQL injection detection rules in front of ISE API endpoints
• Disable or limit REST API functionality if not required for operational purposes until patches can be applied

# Example: Restrict ISE REST API access to management subnet only
# Configure on network firewall or ISE interface ACL
# Allow only trusted management network to access API port
iptables -A INPUT -p tcp --dport 443 -s 10.0.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP