CVE-2024-4555

Executive Summary

CVE-2024-4555 is an Improper Privilege Management vulnerability in OpenText NetIQ Access Manager. This flaw allows an authenticated attacker to impersonate another user under specific, unconfirmed conditions. The vulnerability affects versions prior to 5.0.4.1 and 5.1. With a CVSS score of 7.7, the impact is high for confidentiality and integrity, though availability is not affected. No public proof-of-concept or exploit code is currently available, and the EPSS score is 0.0%, indicating a low probability of exploitation in the wild at this time. The vendor has released patches, and immediate upgrade is recommended.

CVSS Breakdown & Threat Level

• CVSS Score: 7.7 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: Low (PR:L)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: None (A:N)

Threat Level: High. The vulnerability allows an authenticated user to impersonate another user, potentially gaining unauthorized access to sensitive data or performing actions with elevated privileges. The low attack complexity and no user interaction requirement make it attractive to attackers once a foothold is established.

Deep Dive & Mechanics

The vulnerability resides in the privilege management logic of NetIQ Access Manager. Under specific, undisclosed conditions, the application fails to properly validate or enforce user identity during session or request handling. This allows an attacker with low-level authenticated access to craft requests that are processed under the identity of another user.

The root cause is an improper privilege management flaw (CWE-269). The application likely uses a flawed mechanism for user impersonation or session binding, where a user identifier can be manipulated or reused without proper authorization checks. The exact trigger condition is not publicly documented, but it likely involves a race condition, session fixation, or improper handling of authentication tokens.

Vulnerable vs. Patched Code

No specific code diff is publicly available. However, the patch addresses the privilege management logic to ensure that user identity is correctly validated and cannot be manipulated by an authenticated attacker. The fix likely involves:

• Strengthening session token validation.
• Adding authorization checks before processing user impersonation requests.
• Ensuring that user context is not inherited from previous requests without proper verification.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to a vulnerable NetIQ Access Manager instance (version < 5.0.4.1 or < 5.1).
• Valid low-privileged user credentials.

Exploitation Steps:

1. Authenticate to the NetIQ Access Manager as a low-privileged user.
2. Identify the specific endpoint or functionality that is vulnerable to user impersonation. This may require reverse engineering or fuzzing.
3. Craft a request that manipulates the user identifier (e.g., session token, user ID parameter) to impersonate a target user (e.g., an administrator).
4. Send the crafted request and observe if the server processes it under the target user's identity.
5. If successful, perform actions as the impersonated user, such as accessing sensitive data or escalating privileges.

Note: No public exploit code is available. The exact exploitation technique is unknown.

Blue Team

Detection:

• Monitor for unusual authentication patterns, such as a single user account generating multiple session tokens or accessing resources outside their normal scope.
• Log and alert on failed authentication attempts followed by successful impersonation.
• Use the detection rules provided in the Detection Engineering section.

Hunting:

• Search for logs where a user's session token is reused or manipulated.
• Look for requests that contain user identifiers that do not match the authenticated user.

Mitigation:

• Immediately apply the vendor patch.
• If patching is not possible, restrict network access to the NetIQ Access Manager and monitor for suspicious activity.
• Implement additional authentication controls, such as multi-factor authentication (MFA).

Indicators of Compromise (IOCs)

• Network: Unusual HTTP requests to NetIQ Access Manager endpoints with manipulated user identifiers.
• Logs: Log entries showing user impersonation events or privilege escalation.
• System: Unexpected changes to user permissions or access rights.

Specific IOCs:

• Repeated requests to /nidp/ or similar endpoints with varying userid or sessionid parameters.
• Log entries with impersonation or user context anomalies.

Detection Engineering

YARA Rule

rule CVE_2024_4555_NetIQ_Impersonation {
    meta:
        description = "Detects potential exploitation of CVE-2024-4555 in NetIQ Access Manager logs"
        author = "Valters IT"
        date = "2024-10-27"
        reference = "CVE-2024-4555"
    strings:
        $s1 = "impersonation" nocase
        $s2 = "user context" nocase
        $s3 = "sessionid" nocase
        $s4 = "userid" nocase
    condition:
        any of ($s1, $s2) and any of ($s3, $s4)
}

Sigma Rule

title: CVE-2024-4555 - NetIQ Access Manager User Impersonation
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential exploitation of CVE-2024-4555 in NetIQ Access Manager logs
author: Valters IT
date: 2024-10-27
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-4555
logsource:
    product: netiq
    service: access_manager
detection:
    selection:
        EventID: 4624  # Example: Successful logon
        TargetUserName|re: '.*impersonation.*|.*user context.*'
    condition: selection
falsepositives:
    - Legitimate administrative actions
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-4555 - NetIQ Access Manager User Impersonation Attempt"; flow:to_server; content:"/nidp/"; http_uri; pcre:"/(userid|sessionid)=[^&]+/i"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade NetIQ Access Manager to version 5.0.4.1 or 5.1 (latest patch level).
2. If patching is not possible, restrict network access to the vulnerable system and monitor for suspicious activity.

Long-term Measures:

• Implement the principle of least privilege for all user accounts.
• Enable detailed logging and monitoring for authentication and authorization events.
• Regularly review and update security patches.

Workarounds:

• No official workaround is available. Patching is the only recommended solution.

Valters IT