CVE-2017-8540
Microsoft Malware Protection Engine Improper Restriction of Operations Vulnerability
Description
CVE-2017-8540 is a remote code execution vulnerability in Microsoft Malware Protection Engine. The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to memory corruption. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability". Successful exploitation could allow an attacker to execute arbitrary code or cause a denial-of-service condition on affected devices. CISA has added CVE-2017-8540 to the Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. The EPSS score of 84.61% (99.3th percentile) indicates a high likelihood of exploitation activity.
KEV Information
CVSS Score
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | malware protection engine | >= 1.1.13701.0, < 1.1.13704.0 |
| microsoft | endpoint protection | - |
| microsoft | exchange server | 2013; 2016 |
| microsoft | forefront endpoint protection | -; 2010 |
| microsoft | forefront security | - |
| microsoft | intune endpoint protection | - |
| microsoft | security essentials | - |
| microsoft | system center endpoint protection | - |
| microsoft | windows defender | - |
Multiple CVSS Assessments
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- http://www.securityfocus.com/bid/98703(Broken Link, Third Party Advisory, VDB Entry)
- http://www.securitytracker.com/id/1038571(Broken Link, Third Party Advisory, VDB Entry)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8540(Mitigation, Patch, Vendor Advisory)
- https://www.exploit-db.com/exploits/42088/(Exploit, Third Party Advisory, VDB Entry)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-8540(US Government Resource)
Weakness Type
CWE-787: Out-of-bounds Write
Out-of-bounds Write is a vulnerability that occurs when software writes data to a memory location outside the intended boundaries of a buffer. This can happen through buffer overflows, incorrect array indexing, pointer arithmetic errors, or integer overflows affecting size calculations.
Learn more: CWE-787 — Out-of-bounds Write
Impact Analysis
CVE-2017-8540 poses a severe threat to organizations running Microsoft Malware Protection Engine, as it enables unauthenticated attackers to execute arbitrary code on affected devices. With a CVSS score of 7.8 (HIGH), the vulnerability allows attackers operating from the local system to compromise the affected device. A successful attack could lead to full device takeover, allowing adversaries to intercept network traffic, modify routing configurations, and use compromised devices as pivot points for lateral movement within the network. Given the critical role of endpoint protection in enterprise environments, compromise could disable security defenses and expose the organization to further attacks.
Exploit Maturity
CVE-2017-8540 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming that this vulnerability has been exploited in real-world attacks. The EPSS score of 84.61% (99.3th percentile) places it among the most likely vulnerabilities to be exploited. Public exploit code is available, which significantly lowers the barrier for potential attackers. Organizations should treat this vulnerability as an active and ongoing threat requiring immediate remediation.
Remediation
- Apply vendor updates immediately as required by CISA KEV: Apply updates per vendor instructions.
- If immediate patching is not possible, implement interim mitigations such as restricting access to the affected malware scanning engine to trusted networks only using access control lists.
- Monitor affected devices for signs of exploitation, including unexpected reloads, unusual network traffic, and anomalous process behavior.
- Audit compromised devices for unauthorized configuration changes, unexpected user accounts, and persistent backdoors.
- Consider implementing network segmentation to limit the blast radius of a compromised endpoint.
Technical Details
CVE-2017-8540 is a remote code execution vulnerability in the affected component of Microsoft Malware Protection Engine. The vulnerability allows an unauthenticated local attacker to provide a specially crafted input to trigger an out-of-bounds memory write, potentially leading to arbitrary code execution with elevated privileges. The CVSS v3.1 score of 7.8 reflects low attack complexity with user interaction required, and high impact across confidentiality, integrity, and availability. The attack is conducted via local.
Frequently Asked Questions
Is CVE-2017-8540 being actively exploited?
Yes. CVE-2017-8540 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming active exploitation. The EPSS score of 84.61% (99.3th percentile) further indicates a high likelihood of ongoing exploitation.
What products are affected by CVE-2017-8540?
CVE-2017-8540 affects Microsoft Malware Protection Engine. Specifically, affected products include Microsoft Malware Protection Engine, Microsoft Endpoint Protection, Microsoft Exchange Server, Microsoft Forefront Endpoint Protection, Microsoft Forefront Security, Microsoft Intune Endpoint Protection, Microsoft Security Essentials, Microsoft System Center Endpoint Protection, Microsoft Windows Defender.
How do I fix CVE-2017-8540?
Apply updates per vendor instructions. As this vulnerability allows remote code execution, prioritize patching immediately. If patching is delayed, restrict access to the vulnerable malware scanning engine and monitor for exploitation attempts.
How severe is CVE-2017-8540?
CVE-2017-8540 has a CVSS score of 7.8 (HIGH). This is a high-severity vulnerability that enables remote code execution, which could lead to complete compromise of endpoint security defenses. The combination of no authentication requirement and low attack complexity makes this a significant threat.
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