Security Fix JVN#74210258: Stored XSS.

Thanks to Ryoya Koyama of Mitsui Bussan Secure Directions, Inc and xet7 !
This commit is contained in:
Lauri Ojansivu 2025-10-10 23:06:06 +03:00
parent 2e91a359f5
commit e1fa607f87
4 changed files with 60 additions and 2 deletions

View file

@ -91,6 +91,24 @@ Attachments = new FilesCollection({
const ret = fileStoreStrategyFactory.storagePath;
return ret;
},
onBeforeUpload(file) {
// Block SVG files for attachments to prevent XSS attacks
if (file.name && file.name.toLowerCase().endsWith('.svg')) {
if (process.env.DEBUG === 'true') {
console.warn('Blocked SVG file upload for attachment:', file.name);
}
return 'SVG files are not allowed for attachments due to security reasons. Please use PNG, JPG, GIF, or other safe formats.';
}
if (file.type === 'image/svg+xml') {
if (process.env.DEBUG === 'true') {
console.warn('Blocked SVG MIME type upload for attachment:', file.type);
}
return 'SVG files are not allowed for attachments due to security reasons. Please use PNG, JPG, GIF, or other safe formats.';
}
return true;
},
onAfterUpload(fileObj) {
// current storage is the filesystem, update object and database
Object.keys(fileObj.versions).forEach(versionName => {

View file

@ -85,6 +85,21 @@ Avatars = new FilesCollection({
return ret;
},
onBeforeUpload(file) {
// Block SVG files for avatars to prevent XSS attacks
if (file.name && file.name.toLowerCase().endsWith('.svg')) {
if (process.env.DEBUG === 'true') {
console.warn('Blocked SVG file upload for avatar:', file.name);
}
return 'SVG files are not allowed for avatars due to security reasons. Please use PNG, JPG, or GIF format.';
}
if (file.type === 'image/svg+xml') {
if (process.env.DEBUG === 'true') {
console.warn('Blocked SVG MIME type upload for avatar:', file.type);
}
return 'SVG files are not allowed for avatars due to security reasons. Please use PNG, JPG, or GIF format.';
}
if (file.size <= avatarsUploadSize && file.type.startsWith('image/')) {
return true;
}

View file

@ -17,12 +17,26 @@ export const httpStreamOutput = function(readStream, name, http, downloadFlag, c
if (cacheControl) {
http.response.setHeader('Cache-Control', cacheControl);
}
// Set Content-Disposition header
http.response.setHeader('Content-Disposition', getContentDisposition(name, http?.params?.query?.download));
// Add security headers to prevent XSS attacks
const isSvgFile = name && name.toLowerCase().endsWith('.svg');
if (isSvgFile) {
// For SVG files, add strict CSP to prevent script execution
http.response.setHeader('Content-Security-Policy', "default-src 'none'; script-src 'none'; object-src 'none';");
http.response.setHeader('X-Content-Type-Options', 'nosniff');
http.response.setHeader('X-Frame-Options', 'DENY');
}
};
/** will initiate download, if links are called with ?download="true" queryparam */
const getContentDisposition = (name, downloadFlag) => {
const dispositionType = downloadFlag === 'true' ? 'attachment;' : 'inline;';
// Force attachment disposition for SVG files to prevent XSS attacks
const isSvgFile = name && name.toLowerCase().endsWith('.svg');
const forceAttachment = isSvgFile || downloadFlag === 'true';
const dispositionType = forceAttachment ? 'attachment;' : 'inline;';
const encodedName = encodeURIComponent(name);
const dispositionName = `filename="${encodedName}"; filename=*UTF-8"${encodedName}";`;

View file

@ -53,7 +53,18 @@ if (Meteor.isServer) {
// Set appropriate headers
res.setHeader('Content-Type', attachment.type || 'application/octet-stream');
res.setHeader('Content-Length', attachment.size || 0);
res.setHeader('Content-Disposition', `attachment; filename="${attachment.name}"`);
// Force attachment disposition for SVG files to prevent XSS attacks
const isSvgFile = attachment.name && attachment.name.toLowerCase().endsWith('.svg');
const disposition = isSvgFile ? 'attachment' : 'attachment'; // Always use attachment for legacy files
res.setHeader('Content-Disposition', `${disposition}; filename="${attachment.name}"`);
// Add security headers for SVG files
if (isSvgFile) {
res.setHeader('Content-Security-Policy', "default-src 'none'; script-src 'none'; object-src 'none';");
res.setHeader('X-Content-Type-Options', 'nosniff');
res.setHeader('X-Frame-Options', 'DENY');
}
// Get GridFS stream for legacy attachment
const fileStream = getOldAttachmentStream(attachmentId);