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fix(browser): block Azure instance metadata endpoint (SSRF) #182

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fix(browser): block Azure instance metadata endpoint (SSRF) #182

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3 changes: 3 additions & 0 deletions electron/services/BrowserService.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,9 @@ function isBlockedBrowserHost(hostname: string): boolean {
if (normalized === '::1' || normalized === '[::1]') return false
if (normalized === '0.0.0.0' || normalized === '::') return true
if (normalized === 'metadata.google.internal') return true
// Azure Instance Metadata Service — a fixed public-looking IP that resolves to
// host-only metadata (credentials). Not covered by the RFC1918 ranges below.
if (normalized === '168.63.129.16') return true
if (normalized.endsWith('.local') || normalized.endsWith('.internal')) return true

if (/^127\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.test(normalized)) return false
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8 changes: 8 additions & 0 deletions test/services/BrowserService.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,14 @@ describe('BrowserService.navigate', () => {
await expect(navigate('http://169.254.169.254/latest/meta-data')).rejects.toThrow(/blocked/i)
})

it('rejects cloud instance metadata endpoints', async () => {
// AWS/GCP IMDS link-local, GCP metadata hostname, and the Azure IMDS IP
// (a fixed public-looking address that the RFC1918 ranges do not catch).
await expect(navigate('http://169.254.169.254/latest/meta-data/iam/')).rejects.toThrow(/blocked/i)
await expect(navigate('http://metadata.google.internal/computeMetadata/v1/')).rejects.toThrow(/blocked/i)
await expect(navigate('http://168.63.129.16/metadata/instance')).rejects.toThrow(/blocked/i)
})

it('rejects internal domains and credentialed urls', async () => {
await expect(navigate('http://db.internal')).rejects.toThrow(/blocked/i)
await expect(navigate('https://user:pass@example.com')).rejects.toThrow(/blocked/i)
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