Description
A critical vulnerability has been identified in the Remote Desktop Services component of Microsoft Windows, referred to as CVE-2019-1182. This vulnerability enables an unauthenticated attacker to execute arbitrary code on the targeted system through specially crafted requests sent via RDP (Remote Desktop Protocol). As the vulnerability is pre-authentication and requires no user interaction, it poses a significant threat to the security of affected systems. An attacker leveraging this vulnerability could essentially take full control of the system, potentially installing malicious programs, altering or deleting data, and creating accounts with full user rights.
Affected Product(s)
- Microsoft Windows 10 (All versions including x86 and x64 configurations)
- Remote desktop services for Android, and
- Remote desktop services for iOS.
Technical Details
CVE-2019-1182 affects Remote Desktop Services (formerly Terminal Services) and is considered a critical remote code execution vulnerability. The vulnerability can be exploited over RDP by sending specially crafted requests to the Remote Desktop Service component of the Windows OS in an unauthenticated manner.
The vulnerability is assigned a CVSSv3 score of 9.8, reflecting its severe potential impact. One of the key aspects that make this vulnerability particularly dangerous is the absence of any need for user interaction, as well as the fact that it is triggered pre-authentication. This means that simply having RDP open and accessible to attackers is sufficient for exploitation. The code injection occurs because of improper handling of connection requests by the Remote Desktop Services.
Microsoft has emphasized the urgency of this issue due to the ‘wormable’ nature of CVE-2019-1182. Wormable vulnerabilities can propagate throughout networks, responding to the behavior seen in malware such as the WannaCry ransomware. Wormable exploits allow attackers to create self-spreading malware, enabling attacks to move from one vulnerable system to another without human intervention.
Various patches and updates were issued by Microsoft under different KB numbers such as KB4512497, KB4512501, and KB4512516. These cover multiple versions including Windows 7 SP1, Windows Server 2008 R2 SP1, Windows Server 2012, Windows 8.1, Windows Server 2012 R2, and all supported versions of Windows 10 including server variants. Notably, Windows XP, Windows Server 2003, and Windows Server 2008 are not affected, nor is the RDP protocol itself.
An associated risk mentioned in the accompanying security advisories includes potential Denial of Service (DoS) attacks when the script engine or HTTP/2 protocol stack mishandle specially crafted requests. This mismanagement could lead the server to become unresponsive, further amplifying the level of security threat. Moreover, elevation of privilege vulnerabilities exists wherein objects in memory are improperly controlled, allowing for an escalated security context that an attacker could exploit to run arbitrary code.
The vendor issued mitigations and workarounds while also strongly encouraging users to apply patches immediately to prevent potential exploitation. The patched versions effectively resolve this vulnerability by correcting how the Connection Requests are managed within the Remote Desktop Services.
The vulnerability has stirred significant attention in the cybersecurity community, urging rapid action from any organization relying on affected operating systems to ensure their systems’ security. As a particularly dangerous and critical exploit, the broad impact and potential for widespread damage underline the necessity for immediate and comprehensive responses to software updating and security practices.
Weakness
The primary weakness associated with CVE-2019-1182 is identified as an improper control of the generation of code (‘Code Injection’), documented under CWE-94. This weakness allows attackers to send specially crafted requests to the Remote Desktop Service, which could incorporate malicious code through unchecked connections, leading to unauthorized code execution.
Impact Assessment
If successfully exploited, this vulnerability could allow an attacker to gain unauthorized access to sensitive data or execute arbitrary code on the affected system. Once compromised, the attacker can install and execute malicious programs, view, change, or delete data, or create new accounts with full user rights. Given the pre-authentication nature of the vulnerability, it can severely disrupt the functionality of affected systems, leading to potential denial of services and the spread of ‘wormable’ malware across various systems within a network.
Active Exploitation
As of the time the information was compiled, there has been no evidence that CVE-2019-1182 has been exploited in the wild. Microsoft confirmed that this vulnerability was identified during internal efforts to strengthen the Remote Desktop Services, and there were no indications of third parties exploiting it at the time. However, due to the critical nature and potential for exploitation, rapid patching and mitigation measures are strongly recommended to prevent future incidents.
Ransomware Association
This vulnerability bears similarities in potential impact to previously seen exploits leveraged by ransomware attacks, such as the BlueKeep vulnerability. As with BlueKeep, CVE-2019-1182 is considered a wormable exploit, allowing ransomware like WannaCry to propagate without human intervention. This vulnerability can be similarly weaponized by future ransomware variants to gain initial access to the system and spread across networks, elevating the severity of the risks for unpatched systems.
Mitigation and Resolution
Microsoft has released a series of patches addressing this vulnerability. To secure systems, users are advised to update to the latest versions provided in Microsoft’s security updates. For those managing systems manually, relevant KB numbers include updates like KB4512497, KB4512501, and KB4512516 that need to be promptly applied. Additionally, mitigations and workarounds are also available for addressing this vulnerability through Microsoft’s security advisory. Singapore Follows, administrators should ensure robust monitoring of network traffic for signs of abnormal activities and continue to practice best cybersecurity hygiene, including reducing the attack surface by limiting RDP access to trusted hosts or employing VPN solutions for remote access.
Recommendations
- We strongly recommend that all customers apply the latest patch as soon as possible.
- Ensure that Windows 10 systems are updated to versions as applied in KB4512497, KB4512501, and KB4512516, among other updates.
- Implement network-level authentication (NLA) on affected systems to provide an additional layer of security.
- Keep Remote Desktop Services disabled unless essential.
- Restrict RDP access using firewalls or VPNs, ensuring only trusted sources can connect.
- Conduct regular vulnerability assessments and penetration testing to identify and remediate weaknesses.
- Monitor network traffic and logs for unusual activities associated with RDP.
- Educate users about the risks of enabling RDP and best security practices for system access.
- Backup critical data regularly and ensure backup systems are not connected to the main networks.
References ย
- Huawei Security Advisories
- CERT-Portal Details
- Microsoft Security Advisory 1
- Microsoft Security Advisory 2
- Microsoft Update Guide for CVE-2019-1182
- CVE MITRE Details
- NVD Database
- Blog: The Latest on BlueKeep and DejaBlue
- Blog: Microsoft Fixes Two Wormable Vulnerabilities as Part of Massive Patch