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harden(api): escape HTML in email alerts + tighten events-endpoint authz #10

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harden(api): escape HTML in email alerts + tighten events-endpoint authz #10

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5 changes: 4 additions & 1 deletion packages/api/src/routes/agent-guard/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -47,8 +47,11 @@ function clampStr(v: unknown, max = MAX_STR): string | undefined {

/**
* POST /agent-guard/events — record a budget trip; fan out alerts on block.
*
* Requires kill_switch:trigger (owner/admin/member): an agent block IS a
* kill-switch action, so reporting one is a write that viewers shouldn't make.
*/
agentGuardRouter.post("/events", requirePermission("cloud_accounts:read"), async (req, res, next) => {
agentGuardRouter.post("/events", requirePermission("kill_switch:trigger"), async (req, res, next) => {
try {
const guardianAccountId = (req as any).guardianAccountId as string;
const orgId = guardianAccountId;
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38 changes: 29 additions & 9 deletions packages/api/src/services/alerting.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,26 @@ type Severity = "critical" | "error" | "warning" | "info";

const GITHUB_API_HOST = "api.github.com";

/**
* Escape a value for safe interpolation into HTML. Alert details can carry
* user-controlled strings (e.g. a cloud account's `name` from request body,
* or a violation's serviceName), and the email channel renders them into an
* HTML body — so every interpolated string must be escaped to prevent HTML
* injection. Non-string values are stringified first.
*
* Other channels (Slack/Discord/PagerDuty/webhook) transmit via JSON and render
* values as text, so they don't need this; Slack/Discord markdown formatting
* from a crafted string is cosmetic only.
*/
function escapeHtml(value: unknown): string {
return String(value ?? "")
.replace(/&/g, "&")
.replace(/</g, "&lt;")
.replace(/>/g, "&gt;")
.replace(/"/g, "&quot;")
.replace(/'/g, "&#39;");
}

/**
* SSRF Protection: Validate webhook URLs are safe to call.
* Blocks private/internal IPs and non-HTTPS URLs.
Expand Down Expand Up @@ -186,17 +206,17 @@ async function alertEmail(channel: AlertChannel, summary: string, severity: Seve
const violationRows = violations.map((v: any) => {
const multiplier = v.threshold > 0 ? `${Math.round(v.currentValue / v.threshold)}×` : "";
return `<tr>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${v.serviceName ?? ""}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${v.metricName ?? ""}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;color:#ff6b6b;">${v.currentValue ?? ""}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${v.threshold ?? ""}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${escapeHtml(v.serviceName)}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${escapeHtml(v.metricName)}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;color:#ff6b6b;">${escapeHtml(v.currentValue)}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;">${escapeHtml(v.threshold)}</td>
<td style="padding:6px 12px;border-bottom:1px solid #2a2f4a;font-weight:bold;color:#ff6b6b;">${multiplier}</td>
</tr>`;
}).join("");

const actionsTaken = (details.actionsTaken as string[] | undefined) ?? [];
const actionsHtml = actionsTaken.length > 0
? `<p style="color:#4ade80;"><strong>Kill Switch action taken:</strong> ${actionsTaken.join(", ")}</p>`
? `<p style="color:#4ade80;"><strong>Kill Switch action taken:</strong> ${actionsTaken.map(escapeHtml).join(", ")}</p>`
: "";

const html = `<!DOCTYPE html>
Expand All @@ -212,11 +232,11 @@ async function alertEmail(channel: AlertChannel, summary: string, severity: Seve
</p>

<div style="background:rgba(255,107,107,0.08);border:1px solid rgba(255,107,107,0.2);border-radius:8px;padding:16px;margin-bottom:24px;">
<p style="color:#fff;font-size:15px;font-weight:600;margin:0 0 4px;">${summary}</p>
<p style="color:#fff;font-size:15px;font-weight:600;margin:0 0 4px;">${escapeHtml(summary)}</p>
<p style="color:#9ca3af;font-size:13px;margin:0;">
Provider: <strong style="color:#fff;">${String(details.provider ?? "")}</strong> ·
Account: <strong style="color:#fff;">${String(details.accountName ?? "")}</strong> ·
Severity: <strong style="color:#ff6b6b;">${severity}</strong>
Provider: <strong style="color:#fff;">${escapeHtml(details.provider)}</strong> ·
Account: <strong style="color:#fff;">${escapeHtml(details.accountName)}</strong> ·
Severity: <strong style="color:#ff6b6b;">${escapeHtml(severity)}</strong>
</p>
</div>

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17 changes: 17 additions & 0 deletions packages/api/tests/services/alerting.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -440,6 +440,23 @@ describe("Alerting Service", () => {
expect(payload.text).toBeDefined();
});

it("escapes HTML in user-controlled fields (accountName, serviceName, summary)", async () => {
// accountName traces to req.body.name at cloud-account creation — user-controlled.
const xss = `<script>alert('x')</script>`;
await sendAlerts([emailChannel()], `summary ${xss}`, "critical", {
provider: "cloudflare",
accountName: `acct ${xss}`,
violations: [{ serviceName: `svc ${xss}`, metricName: "CPU", currentValue: 1, threshold: 0, severity: "critical" }],
actionsTaken: [`disconnect ${xss}`],
});

const [payload] = mockResendSend.mock.calls[0];
// The raw <script> tag must never appear in the rendered HTML…
expect(payload.html).not.toContain("<script>");
// …but the escaped form should, proving the content is preserved, just neutralized.
expect(payload.html).toContain("&lt;script&gt;");
});

it("subject includes severity emoji and uppercased severity", async () => {
await sendAlerts([emailChannel()], "Cost runaway", "critical", {
provider: "cloudflare", accountName: "zombay-cf", violations,
Expand Down