Microsoft SharePoint Remote Code Execution Vulnerability (CVE-2019-0604)
Published In CISA KEV since Sources: CVE.org
What is affected, what to do
A remote code execution vulnerability exists in Microsoft SharePoint when the software fails to check the source markup of an application package, aka 'Microsoft SharePoint Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2019-0594.
The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. 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 SharePoint Server
eq 2010 Service Pack 2..2010 Service Pack 2 - Microsoft SharePoint Server
eq 2019..2019 - Microsoft SharePoint Foundation
eq 2013 Service Pack 1..2013 Service Pack 1 - Microsoft SharePoint Enterprise Server
eq 2016..2016
- Microsoft SharePoint Server
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Metrics
9.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
9.8
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: CVE.org
99.91 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.97
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- 253.95 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- 9.8 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- 9.8
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- 99.91 %
- 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- 99.97
- 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
Response and mitigation
Why act now?
Prioritisation rationale
This flaw is network-reachable without authentication or user interaction and yields full code execution as the farm account. Public exploits have circulated for years. It ranks among the CVEs most likely to be exploited, and CISA flags it for known ransomware use. Attackers use it as an initial-access vector against internet-facing SharePoint at government bodies, utilities and mid-market firms, then follow up with webshell persistence, credential theft and lateral movement toward domain compromise. Treat any externally reachable, unpatched farm as a critical emergency and assume it is compromised until proven otherwise. Internal-only farms remain high priority because they are a favoured pivot point once an attacker has a foothold.
Runbook step 1
Immediate response (0-24 h)
- Apply the CVE-2019-0604 security update to every server in the SharePoint farm (WFE, App and Search). KB numbers vary by product version: a patch is available from the vendor, so look up the version in the Microsoft Security Update Guide entry for CVE-2019-0604. Microsoft re-released a revised update after the initial one. Confirm the revised package is installed, not just the first release, and then run the SharePoint Products Configuration Wizard (PSConfig).
- Inventory internet-facing SharePoint immediately. This covers direct exposure on 80/443 and anything published through a reverse proxy, ADFS or WAP. Pull unpatched instances off the internet, or put them behind VPN or pre-authentication, until they are patched.
- Hunt for compromise before declaring the system clean. Check
C:\Program Files\Common Files\microsoft shared\Web Server Extensions\<version>\TEMPLATE\LAYOUTS\and the IIS webroots for new or modified.aspx,.ashxand.asmxfiles. China Chopper-style webshells are the classic artefact. On any hit, isolate the host and trigger incident response. NIS2 entities must also meet the 24-hour early-warning deadline. - Rotate the farm account and application-pool identities if there is any indication of exploitation, because the attacker's code runs as these accounts. Also rotate service accounts with SQL access and any Secure Store credentials.
- Contain lateral movement if the farm is compromised. Restrict outbound traffic from the SharePoint servers to what is strictly required. Review farm-account logons on other hosts (Event 4624, logon type 3/10).
Runbook step 2
Mitigation layers
- Network segmentation: Put SharePoint in a dedicated zone. Allow inbound 443 only from the reverse proxy. Deny outbound internet access except for explicitly required update endpoints, which leaves webshells and reverse shells without a callback path.
- WAF/IPS: Block or tightly inspect external POSTs to
/_layouts/*/Picker.aspxand similar picker endpoints. Pay particular attention to oversized serialised or XML-like values inctl00$PlaceHolderDialogBodySection$ctl05$hiddenSpanData. Enable the available CVE-2019-0604 signatures (ET Snort/Suricata rules and vendor IPS). - Upstream authentication: Publish SharePoint externally only behind reverse-proxy pre-authentication with MFA. Disable anonymous access on web applications unless there is a hard business requirement for it.
- Endpoint hardening: Use WDAC/AppLocker or ASR rules to stop
w3wp.exefrom spawningcmd.exe,powershell.exe,rundll32.exeorcertutil.exe. Keep real-time AV and AMSI integration enabled on SharePoint servers. - Least privilege: Farm and app-pool accounts must not be Domain Admins or local admins elsewhere. Deny them interactive logon on workstations via GPO.
Runbook step 3
Detection rules
- IIS access logs: Look for POSTs to
Picker.aspxwith abnormal request sizes or from external IPs. SPL:index=iis cs_method=POST cs_uri_stem="*/_layouts/*Picker.aspx" | stats count by c_ip, cs_uri_stem - Process ancestry (Sysmon EID 1 / Security 4688): Alert when
w3wp.exespawns a shell or LOLBin. KQL:DeviceProcessEvents | where InitiatingProcessFileName =~ "w3wp.exe" and FileName in~ ("cmd.exe","powershell.exe","certutil.exe","rundll32.exe") - File creation (Sysmon EID 11): Alert when
w3wp.exewrites.aspx,.ashxor.asmxfiles intoLAYOUTSor a webroot. Sigma shape:Image|endswith: '\w3wp.exe'withTargetFilename|endswith: '.aspx'. - Network telemetry (Zeek/Suricata, Sysmon EID 3): Watch for SharePoint hosts initiating connections to internet IPs or unusual internal targets (SMB/445, RDP/3389, WinRM/5985). These are often followed by HTTP requests to previously unseen
.aspxpaths. - Account anomalies: Flag the farm or app-pool account appearing in 4624/4648 events on other hosts, or alongside credential-dumping indicators such as LSASS access (Sysmon EID 10).
- IIS access logs: Look for POSTs to
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
A remote code execution vulnerability exists in Microsoft SharePoint when the software fails to check the source markup of an application package, aka 'Microsoft SharePoint Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2019-0594.
Source: cvelistv5, CISA KEV Catalog, NVD (NIST)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server |
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| Microsoft | Microsoft SharePoint Foundation |
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| Microsoft | Microsoft SharePoint Server |
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| microsoft | sharepoint_enterprise_server |
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| microsoft | sharepoint_foundation |
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| microsoft | sharepoint_server |
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Vendors and products
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
- securityfocus.com106914Vulnerability database, x_refsource_BID
- portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2019-0604x_refsource_CONFIRM
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2019-0604government-resource
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