A hostile ERC-20's symbol() reached an innerHTML string unescaped, and neither manifest declared default-src, so an attacker deploying a token with 1,000+ holders and airdropping one unit could render a full-viewport cross-origin iframe over the wallet's own UI, on screens where the user types their password. escapeHtml is now a pure string replace over & < > " ' — the old version round-tripped through textContent, which escapes neither quote, while already being used inside data-copy="...". All 19 files in src/popup/views/ were audited: beyond the reported symbol site, the explorer-supplied directionLabel in all three transaction lists, wallet.name, addr.ensName, the blockie data: URIs and two ad-hoc quote-only escapes were also unescaped. Explorer URLs now go through one helper that percent-encodes the path segment. Both manifests add default-src 'self', frame-src 'none', form-action 'none' and base-uri 'none'. Three loosenings are pinned in tests/manifest.test.js and justified in README.md: style-src 'unsafe-inline' (39 static style attributes; Firefox implements neither style-src-attr nor 'unsafe-hashes'), img-src data: (blockies), connect-src https: http: (user-configurable RPC). Note frame-src 'none' blocks a frame loading, not the element existing, so the zero-iframe assertion is a claim about the escaping alone; the test asserts the element count and the literal rendered text separately, taking the count before any click an overlay could intercept. Verified: make check 39 suites / 811 tests, test-e2e 55/55 including the WebAssembly-under-CSP assertion, test-e2e-firefox 8/8, zero CSP violations asserted rather than merely unobserved. Reverting only balanceLine's interpolation reproduces the attack as 2 iframes on the address screen.
152 lines
6.5 KiB
JavaScript
152 lines
6.5 KiB
JavaScript
// The shipped Content Security Policy, pinned in both directions.
|
|
//
|
|
// This is the anti-regression check for #182. libsodium decides its
|
|
// backend by trying to compile WebAssembly and catching the failure, so a
|
|
// CSP that refuses WASM demotes the vault to the wasm2js translation —
|
|
// roughly 20x slower per Argon2id derivation — and says so only in a
|
|
// console message nobody reads. Dropping 'wasm-unsafe-eval' from either
|
|
// manifest therefore has to fail a check, not a log line.
|
|
//
|
|
// It is equally a check against loosening. 'wasm-unsafe-eval' is granted
|
|
// deliberately and narrowly (see the backend note in src/shared/vault.js);
|
|
// 'unsafe-eval', 'unsafe-inline' and any remote script source are not, and
|
|
// an exact match on the token set is what keeps the next edit from
|
|
// smuggling one in alongside.
|
|
//
|
|
// It is also the anti-regression check for #307. The policy used to declare
|
|
// script-src and object-src and nothing else, which left every directive
|
|
// that does not fall back to them — and, absent default-src, every one that
|
|
// does — wide open: a hostile ERC-20 symbol that reached innerHTML could
|
|
// load a full-viewport cross-origin iframe over the wallet's own UI. The
|
|
// escaping in src/shared/html.js is the primary fix; default-src is what
|
|
// stops the next escape that slips from reaching the network.
|
|
//
|
|
// Every directive below is pinned exactly, because each of the four
|
|
// loosenings is load-bearing and none of them may grow:
|
|
//
|
|
// style-src 'unsafe-inline' src/popup/index.html and the view helpers
|
|
// use style="..." attributes throughout, which
|
|
// CSP blocks without it. Chrome enforces this
|
|
// on attributes, not just <style> blocks, and
|
|
// Firefox has never implemented style-src-attr,
|
|
// so there is no narrower spelling available.
|
|
// img-src data: blockies are data: PNGs assigned to img.src.
|
|
// connect-src https: http: the RPC endpoint is user-configurable, and a
|
|
// local node over http://127.0.0.1 is a
|
|
// supported configuration — the Firefox e2e
|
|
// suite runs on exactly that.
|
|
// frame-src/form-action/base-uri named rather than inherited: form-action
|
|
// and base-uri do not fall back to default-src
|
|
// at all, and frame-src 'none' is what kills
|
|
// the reported attack outright.
|
|
//
|
|
// build.js copies these files to dist/<target>/manifest.json verbatim, so
|
|
// what is asserted here is what ships.
|
|
|
|
const fs = require("fs");
|
|
const path = require("path");
|
|
|
|
const MANIFEST_DIR = path.join(__dirname, "..", "manifest");
|
|
|
|
const EXPECTED_DIRECTIVES = {
|
|
"default-src": ["'self'"],
|
|
"script-src": ["'self'", "'wasm-unsafe-eval'"],
|
|
"object-src": ["'self'"],
|
|
"style-src": ["'self'", "'unsafe-inline'"],
|
|
"img-src": ["'self'", "data:"],
|
|
"connect-src": ["'self'", "http:", "https:"],
|
|
"frame-src": ["'none'"],
|
|
"form-action": ["'none'"],
|
|
"base-uri": ["'none'"],
|
|
};
|
|
|
|
// Directives that fetch script. Nothing that can execute code may name a
|
|
// remote source, an eval form, or an inline form; 'wasm-unsafe-eval' is the
|
|
// single deliberate exception and it is pinned above.
|
|
const SCRIPT_DIRECTIVES = ["default-src", "script-src", "object-src"];
|
|
|
|
const FORBIDDEN_SOURCES = [
|
|
"'unsafe-eval'",
|
|
"'unsafe-inline'",
|
|
"http:",
|
|
"https:",
|
|
"data:",
|
|
"blob:",
|
|
"*",
|
|
];
|
|
|
|
function readManifest(name) {
|
|
return JSON.parse(
|
|
fs.readFileSync(path.join(MANIFEST_DIR, name + ".json"), "utf8"),
|
|
);
|
|
}
|
|
|
|
// "script-src 'self'; object-src 'self'" -> { "script-src": ["'self'"], ... }
|
|
function parseCsp(policy) {
|
|
const directives = {};
|
|
for (const part of policy.split(";")) {
|
|
const tokens = part.trim().split(/\s+/).filter(Boolean);
|
|
if (tokens.length === 0) continue;
|
|
directives[tokens[0]] = tokens.slice(1);
|
|
}
|
|
return directives;
|
|
}
|
|
|
|
function assertPolicy(policy) {
|
|
const directives = parseCsp(policy);
|
|
// Exact, in both directions: a directive that appears here and not in
|
|
// EXPECTED_DIRECTIVES is an unreviewed addition, and one that
|
|
// disappears silently reopens whatever it was closing.
|
|
expect(Object.keys(directives).sort()).toEqual(
|
|
Object.keys(EXPECTED_DIRECTIVES).sort(),
|
|
);
|
|
for (const [name, sources] of Object.entries(EXPECTED_DIRECTIVES)) {
|
|
expect([name, directives[name].slice().sort()]).toEqual([
|
|
name,
|
|
sources.slice().sort(),
|
|
]);
|
|
}
|
|
for (const name of SCRIPT_DIRECTIVES) {
|
|
for (const source of FORBIDDEN_SOURCES) {
|
|
expect(name + " " + directives[name].join(" ")).not.toContain(
|
|
" " + source,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
describe("shipped Content Security Policy", () => {
|
|
// MV3 takes an object and applies extension_pages to the popup and the
|
|
// background service worker, which is where libsodium runs.
|
|
test("chrome MV3 ships the pinned policy, default-src included", () => {
|
|
const csp = readManifest("chrome").content_security_policy;
|
|
expect(typeof csp).toBe("object");
|
|
expect(Object.keys(csp)).toEqual(["extension_pages"]);
|
|
assertPolicy(csp.extension_pages);
|
|
});
|
|
|
|
// MV2 takes the policy as a bare string. Firefox does not require
|
|
// 'wasm-unsafe-eval' for MV2 today — enforcement is report-only and
|
|
// Bugzilla 1770909 is still open — so that token is future-proofing
|
|
// for when it lands, not a mandate, and it stays inside Firefox's MV2
|
|
// base-CSP ceiling. object-src 'self' is the load-bearing half: a
|
|
// Firefox before 106 rejects an MV2 policy string that omits
|
|
// object-src and falls back to its own default, discarding everything
|
|
// declared here. Same policy as Chrome, different manifest shape.
|
|
test("firefox MV2 ships the pinned policy, default-src included", () => {
|
|
const csp = readManifest("firefox").content_security_policy;
|
|
expect(typeof csp).toBe("string");
|
|
assertPolicy(csp);
|
|
});
|
|
|
|
// The two targets share one codebase and one crypto path; a policy
|
|
// that drifts apart between them means one of the two builds is
|
|
// running a backend nothing tests.
|
|
test("both targets ship the same policy", () => {
|
|
const chrome =
|
|
readManifest("chrome").content_security_policy.extension_pages;
|
|
const firefox = readManifest("firefox").content_security_policy;
|
|
expect(firefox).toBe(chrome);
|
|
});
|
|
});
|