Microsoft Windows Remote Code Execution Vulnerability (CVE-2014-4148)
Published In CISA KEV since Sources: CVE.org
What is affected, what to do
win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows remote attackers to execute arbitrary code via a crafted TrueType font, as exploited in the wild in October 2014, aka "TrueType Font Parsing Remote Code Execution Vulnerability."
The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.
- Affected
- Microsoft Windows Server 2008
eq r2..r2 - Microsoft Windows Server 2012
eq r2..r2
- Microsoft Windows Server 2008
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Metrics
8.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
8.8
CVSS v3
Severity High on the scale from 0 to 10.
Source: CVE.org
59.9 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.13
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 222.61 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- actively exploited
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 8.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 8.8
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 59.9 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.13
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- Actively exploited
- Published
In CISA KEV since
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- CISA assessment (SSVC)
- Exploitation: active · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 10 February 2025
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-94
Response and mitigation
Why act now?
Prioritisation rationale
This flaw gives kernel-level code execution without authentication. The trigger is a crafted TrueType font delivered in a document attachment or web page. The only requirement is that a user opens or renders it, and no separate privilege-escalation step is needed. Despite its age, it remains among the CVEs most likely to be exploited and was historically used in targeted phishing operations. CISA does not flag known ransomware use. Risk on a currently maintained fleet is low, but it becomes critical wherever Windows 7, Server 2008 or older still processes email or web content. This is typically the case for engineering workstations, HMIs and lab PCs in KRITIS environments. Treat any such exposure as high priority and record it as NIS2-relevant legacy risk in the risk register.
Runbook step 1
Immediate response (0-24 h)
- Inventory: Enumerate every host running Windows Server 2003 SP2, Vista SP2, Server 2008 SP2/R2 SP1, Windows 7 SP1, Windows 8/8.1, Server 2012/2012 R2 and Windows RT/RT 8.1 via CMDB, EDR or AD (
Get-ADComputer -Filter * -Properties OperatingSystem). Focus on legacy boxes in OT, manufacturing, medical and control-room environments. - Patch: Deploy Microsoft's win32k.sys TrueType font parsing update (Security Bulletin MS14-058, KB3000061 — verify against each OS build in the vendor advisory). Confirm installation with
Get-HotFix -Id KB3000061. - Isolate unpatchable hosts: Server 2003 and Vista are end-of-life. Move them into a dedicated segment with no mail client, no web browsing and no Office document handling.
- Tighten the mail gateway: For affected user groups, temporarily route externally sourced Office documents (DOC/DOCX/RTF/XLS/PPT) and PDFs to sandbox detonation or quarantine. Embedded fonts are the typical delivery vehicle.
- Block web fonts: On legacy hosts, disable web font download via GPO: set the IE zone setting "Downloads > Font download" to "Disable" for the Internet and Restricted Sites zones.
- Inventory: Enumerate every host running Windows Server 2003 SP2, Vista SP2, Server 2008 SP2/R2 SP1, Windows 7 SP1, Windows 8/8.1, Server 2012/2012 R2 and Windows RT/RT 8.1 via CMDB, EDR or AD (
Runbook step 2
Mitigation layers
- Network segmentation: Force legacy VLANs through an allowlisting proxy for outbound HTTP/HTTPS. On that proxy, drop
application/x-font-ttf,font/ttf,application/vnd.ms-fontobject(.eot) andfont/wofffrom uncategorised domains. - Mail/content filtering: Detect and strip embedded TrueType fonts using content disarm & reconstruction. For a YARA starting point, look for the
00 01 00 00/74 72 75 65font header inside OLE/RTF objects (\fonttblwith\fontemb). - Endpoint hardening: Enforce Protected View for internet-sourced Office files (Mark of the Web GPO) and block macros and ActiveX. Where still deployed on legacy hosts, enable EMET or EDR exploit protection for WINWORD.EXE, EXCEL.EXE, POWERPNT.EXE, iexplore.exe and AcroRd32.exe.
- IAM/least privilege: Prohibit interactive domain-admin or local-admin use on affected hosts. Because the code runs in kernel context, limit blast radius from credentials cached in LSASS: deploy LAPS and enforce the tiered admin model.
- Application control: Apply AppLocker or SRP allowlisting on legacy hosts so second-stage payloads in
%TEMP%,%APPDATA%and%ProgramData%cannot execute.
- Network segmentation: Force legacy VLANs through an allowlisting proxy for outbound HTTP/HTTPS. On that proxy, drop
Runbook step 3
Detection rules
- Process ancestry (Sysmon EID 1 / Security 4688): Watch for Office apps or browsers spawning
cmd.exe,powershell.exe,rundll32.exeor unknown binaries, especially children atIntegrityLevel=Systemunder a user-context parent. Sigma shape:ParentImage|endswith: ['\winword.exe','\iexplore.exe'] AND IntegrityLevel: System. - Kernel crashes (System log EID 1001 BugCheck, EID 41): Clusters of bluescreens referencing
win32k.syssuggest failed exploitation attempts. KQL:Event | where EventID == 1001 and RenderedDescription has "win32k". - File creation (Sysmon EID 11): Look for
.ttf,.fonor.eotfiles dropped into%TEMP%or INetCache shortly before a new process starts. Also flag writes toC:\Windows\Fontsby non-installer processes. - Network telemetry (Zeek files.log / Suricata fileinfo): Look for font files (
mime_typefont/*) delivered from newly registered or rare domains to legacy subnets. SPL:index=zeek sourcetype=files mime_type="*font*" | stats count by tx_hosts, rx_hosts. - Privilege transitions: Flag Security EID 4672 / EID 4688 with elevated
TokenElevationTypeon workstations without an admin logon, where the process is not parented byservices.exeorwinlogon.exe.
- Process ancestry (Sysmon EID 1 / Security 4688): Watch for Office apps or browsers spawning
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows remote attackers to execute arbitrary code via a crafted TrueType font, as exploited in the wild in October 2014, aka "TrueType Font Parsing Remote Code Execution Vulnerability."
Source: NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)
Vendors and products
- Microsoft Microsoft Windows 7
- Microsoft Microsoft Windows 8 Professional Edition
- Microsoft Microsoft Windows 8.1
- Microsoft Microsoft Windows RT Gold
- Microsoft Microsoft Windows RT 8.1
- Microsoft Microsoft Windows Server 2003
- Microsoft Microsoft Windows Server 2008
- Microsoft Microsoft Windows Server 2012
- Microsoft Microsoft Windows Vista Gold on X64
Affected operating systems
| Windows | microsoft | windows_7 | — |
| Windows | microsoft | windows_8 | — |
| Windows | microsoft | windows_8.1 | — |
| Windows | microsoft | windows_rt | — |
| Windows | microsoft | windows_rt_8.1 | — |
| Windows | microsoft | windows_server_2003 | — |
| Windows | microsoft | windows_server_2008 | r2 |
| Windows | microsoft | windows_server_2008 | — |
| Windows | microsoft | windows_server_2012 | r2 |
| Windows | microsoft | windows_server_2012 | — |
| Windows | microsoft | windows_vista | — |
Weakness classes (CWE)
CWE-94Improper Control of Generation of Code ('Code Injection')
Base
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
Entry at MITRE CWE-94
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| CISA KEV Catalog | CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov | actively exploited |
References & sources
- blogs.technet.comb/srd/archive/2014/10/14/accessing-risk-for-the-october-2014-se…x_refsource_CONFIRM, Not applicable
- secunia.com60970Third-party advisory, x_refsource_SECUNIA, Broken link
- securityfocus.com70429Vulnerability database, x_refsource_BID, Broken link, Third-party advisory, Vulnerability database
- docs.microsoft.comMS14-058Vendor advisory, x_refsource_MS, Patch, Vendor advisory
- exchange.xforce.ibmcloud.comms-kmd-cve20144148-code-exec(96995)Vulnerability database, x_refsource_XF, Third-party advisory, Vulnerability database
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2014-4148government-resource, US government resource
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<a href="https://intel.neosec.eu/en/cve/CVE-2014-4148"><img src="https://intel.neosec.eu/badge/cve/CVE-2014-4148.svg?lang=en" alt="CVE-2014-4148 – NEOSEC Intel" height="20"></a>