Qlik Sense Path Traversal Vulnerability (CVE-2023-41266)
Published In CISA KEV since Sources: pwn.watch, CVE.org
What is affected, what to do
A path traversal vulnerability in Qlik Sense allows an unauthenticated remote attacker to send HTTP requests to unauthorized endpoints, enabling access to sensitive data and limited integrity impact. The vulnerability is actively exploited in the wild and has been added to the CISA Known Exploited Vulnerabilities catalog. Confirmed use in ransomware campaigns makes this a high-priority remediation target for any organization running Qlik Sense, especially internet-facing deployments. A patch is available and should be applied immediately, combined with network-level restrictions to limit exposure until remediation is complete.
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
- Qlik Sense
eq august_2022..august_2022 - Qlik Sense
eq february_2023..february_2023 - Qlik Sense
eq may_2023..may_2023 - Qlik Sense
eq november_2022..november_2022
- Qlik Sense
Not sure whether and how you are affected? Ask a question about this vulnerability
Metrics
8.2
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
8.2
CVSS v3
Severity High on the scale from 0 to 10.
Source: pwn.watch, CVE.org
84.8 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.71
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- 248.86 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- 8.2 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- 8.2
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- 84.8 %
- 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- 99.71
- 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 · automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 29 November 2023
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-22
Response and mitigation
Why act now?
Prioritisation rationale
This flaw is network-reachable without authentication or user interaction. It sits among the CVEs most likely to be exploited, and CISA explicitly flags known ransomware campaign use. In the wild it is chained with CVE-2023-41265 into remote code execution: attackers gain initial access, drop remote-management tools, pivot using the privileged service account and then deploy encryption. Typical victims are mid-market organisations running internet-facing BI portals. Treat any externally reachable or unpatched instance as critical with emergency-change priority, and if indicators are found, NIS2/KRITIS entities should also assess their incident-reporting obligations.
Runbook step 1
Immediate response (0-24 h)
- Patch now: Upgrade Qlik Sense Enterprise for Windows to a fixed build: August 2023 IR, May 2023 Patch 4, February 2023 Patch 8, November 2022 Patch 11 or August 2022 Patch 13. Affected builds are May 2023 Patch 3 and earlier, February 2023 Patch 7 and earlier, November 2022 Patch 10 and earlier, and August 2022 Patch 12 and earlier.
- Go beyond the minimum fix: The original fix was later bypassed (CVE-2023-48365), so move to the latest patch of your release track rather than the minimum version listed here. Patch available from the vendor — look up the exact version in the vendor advisory.
- Remove internet exposure: Until patched, block internet access to the Qlik Sense proxy (443/80) or put it behind VPN/ZTNA. Internal service ports (4242 QRS, 4243 QPS API, 4747 Engine) must never be reachable from outside.
- Start a compromise assessment: Given the confirmed ransomware use, assume any exposed instance may already be compromised. Hunt back to the start of exposure for unexpected child processes of Qlik services, new local accounts and remote-access tooling.
- Rotate credentials: If indicators are present, rotate the Qlik service account, frequently an over-privileged domain account, and the data-source credentials stored on the server.
Runbook step 2
Mitigation layers
- Network segmentation: Place Qlik Sense nodes in a dedicated server segment. Allow outbound traffic only to required data sources and deny internet egress, which cuts off tool staging and C2 after exploitation.
- WAF/reverse proxy: Drop requests to the proxy that contain traversal sequences (
../,..%2f,%2e%2e, double-encoded variants). Also reject malformed header combinations indicative of HTTP request tunnelling, since this bug is chained with CVE-2023-41265; an example is a request carrying bothTransfer-EncodingandContent-Length. - IPS: Enable available Suricata/ET signatures for CVE-2023-41266/41265. Alert on and block unauthenticated requests reaching
/qrs/endpoints via the proxy. - Endpoint hardening: Use EDR custom rules or WDAC/AppLocker to stop Qlik service binaries (
Scheduler.exe,Engine.exe,Repository.exe,Proxy.exe) from spawningcmd.exe,powershell.exe,rundll32.exeormsiexec.exe. - Least privilege: Strip the service account down to the minimum it needs, with no Domain Admin rights and no local admin on other hosts. Disable anonymous access in the virtual proxy configuration ("No anonymous user").
Runbook step 3
Detection rules
- Proxy/web logs: In
C:\ProgramData\Qlik\Sense\Log\Proxy\and any upstream reverse-proxy logs, look for URIs with encoded traversal under/resources/(e.g./resources/qmc/fonts/with..%2f) followed by successful responses on/qrs/. SPL:index=web host=qlik* uri="*/resources/*" (uri="*..%2f*" OR uri="*%2e%2e*") - Sysmon EID 1 / Defender DeviceProcessEvents: Shells spawned by Qlik services. KQL:
DeviceProcessEvents | where InitiatingProcessFileName in~ ("Scheduler.exe","Engine.exe","Repository.exe","Proxy.exe") and FileName in~ ("cmd.exe","powershell.exe","rundll32.exe","msiexec.exe") - Windows Event IDs: 4720/4732 (local account creation or addition to Administrators) and 7045 (new service, e.g. AnyDesk or ScreenConnect) on Qlik hosts. 4624 logon types 3/10 by the Qlik service account on hosts outside the Qlik cluster.
- Network telemetry (Zeek/Suricata): Outbound connections from Qlik servers to unknown destinations, executable downloads, and RDP/SMB lateral movement originating from the Qlik segment. Also watch for HTTP requests to the proxy with duplicate or conflicting length headers.
- Sigma shape:
logsource: process_creationwithParentImage|endswith: '\Scheduler.exe'andImage|endswith: ['\powershell.exe','\cmd.exe'], levelhigh.
- Proxy/web logs: In
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 path traversal vulnerability found in Qlik Sense Enterprise for Windows for versions May 2023 Patch 3 and earlier, February 2023 Patch 7 and earlier, November 2022 Patch 10 and earlier, and August 2022 Patch 12 and earlier allows an unauthenticated remote attacker to generate an anonymous session. This allows them to transmit HTTP requests to unauthorized endpoints. This is fixed in August 2023 IR, May 2023 Patch 4, February 2023 Patch 8, November 2022 Patch 11, and August 2022 Patch 13.
Source: pwn.watch, CISA KEV Catalog, cvelistv5, NVD (NIST), CVE.org (MITRE)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| qlik | qlik_sense |
|
|
Vendors and products
Weakness classes (CWE)
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Base
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Entry at MITRE CWE-22
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
- community.qlik.comt5/Release-Notes/tkb-p/ReleaseNotes
- community.qlik.comVendor advisory: Qlik Sensepwn-watch
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2023-41266government-resource
- pwn.watchpwn.watch: Qlik Sense: 2 exploited vulnerabilities (CVE-2023-41265, CVE-2023-41266)pwn-watch
- NVD (NIST)NVD: CVE-2023-41265pwn-watch
- NVD (NIST)NVD: CVE-2023-41266pwn-watch
- cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch
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<a href="https://intel.neosec.eu/en/cve/CVE-2023-41266"><img src="https://intel.neosec.eu/badge/cve/CVE-2023-41266.svg?lang=en" alt="CVE-2023-41266 – NEOSEC Intel" height="20"></a>