MediumPublic exploit

CORS Bypass in StackStorm Web UI (st2web)

IdentifiersCVE-2019-9580CWE-346

A vulnerability in StackStorm Web UI (st2web) before versions 2.9.3 and 2.10.3 allows attackers to bypass the Cross-Origin Resource Sharing (CORS) protection mechanism by using a "null" origin value. This can enable cross-origin requests that should otherwise be blocked, potentially leading to cross-site scripting (XSS) attacks.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an attacker to bypass CORS restrictions, enabling them to perform unauthorized cross-origin requests. This can lead to XSS, data theft, or actions performed on behalf of authenticated users, depending on the context and the attacker's capabilities.

Mitigation

If you can’t patch tonight, do this now.

As an interim mitigation, restrict access to the StackStorm Web UI to trusted networks and users only, and consider implementing additional web application firewall (WAF) rules to block requests with a "null" origin header.

Remediation

Patch, then assume compromise.

Upgrade StackStorm Web UI (st2web) to version 2.9.3, 2.10.3, or later, where the CORS validation logic has been corrected to properly handle "null" origin values.

PUBLIC EXPLOITS

Exploits

1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos.

VALID 1 / 1 TOTALView more in app

CVE-2019-9580MaturityPoCVerified exploit

This repository demonstrates a proof-of-concept exploit for CVE-2019-9580, a CORS misconfiguration vulnerability in StackStorm versions prior to 2.9.3 and 2.10.3. The exploit leverages the fact that the StackStorm API responds with 'Access-Control-Allow-Origin: null' to requests with an 'Origin: null' header, allowing cross-origin requests from malicious web pages. The attack is browser-based and requires a victim (authenticated to StackStorm) to visit a malicious page (index.html), which uses JavaScript to send a crafted POST request to the StackStorm API endpoint '/api/v1/executions'. The payload triggers the 'core.remote' action to execute arbitrary commands on the StackStorm host, demonstrated by opening a reverse shell to the attacker's machine (172.28.0.1:1337). The README.md provides detailed background, exploitation steps, and references to the vulnerability and its remediation. The repository contains two files: a README.md with technical details and an index.html containing the exploit code. The exploit is a proof-of-concept and does not include advanced payload customization or automation.

mpgnDisclosed Mar 13, 2019javascripthtmlbrowser

EXPOSURE SURFACE

Affected products & vendors

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VendorProductType

StackstormStackstormapplication

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ACTIVITY FEED

Recent activity

No public activity tracked yet. Mallory keeps watching.

0 SOURCESView more in app

No public activity observed for this vulnerability.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

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Social activity