Threats affecting pkg:github/line/centraldogma

## Vulnerability `ZooKeeperReplicationConfig.secret()` silently substitutes the hard-coded constant `"ch4n63m3"` (leetspeak for "change me") whenever the operator omits `replication.secret`. The same secret is wired into both the **client-facing SASL context** and the **quorum/learner SASL contexts** of the embedded ZooKeeper. The constant is in OSS source on GitHub and is discoverable via code search in seconds. ### Three Reinforcing Defects 1. **OSS-public credential** — `DEFAULT_SECRET` is in `line/centraldogma` source. 2. **Silent fallback** — `firstNonNull(convertValue(...), DEFAULT_SECRET)` substitutes the default with no log, no warning, no startup banner. The only sanity check `checkArgument(!secret().isEmpty(), ...)` passes because the getter substitutes the literal before the emptiness check runs. 3. **Dual-purpose secret** — used for both ZK client-port super auth and inter-peer quorum SASL. A single leaked password authenticates against both surfaces. ### Architecture Context (Important) Central Dogma does **NOT** connect to an external ZooKeeper ensemble. Each replica embeds a `QuorumPeer` (`EmbeddedZooKeeper extends QuorumPeer`) inside its own JVM. The Central Dogma cluster **IS** the ZK ensemble. So the "ZK network" is the inter-replica network of the Central Dogma cluster itself. ### Applicability | `replication.method` | ZK Started? | Applicable? | |---|---|---| | `NONE` (standalone, dev default) | No | **NOT applicable** | | `ZOOKEEPER` (HA production) | Yes, embedded on every replica | **Fully applicable** — canonical production configuration | --- ## Evidence **File:** `server/src/main/java/com/linecorp/centraldogma/server/ZooKeeperReplicationConfig.java` **Branch:** `main` @ commit `d64a5151` **Line 53** — the constant: ```java private static final String DEFAULT_SECRET = "ch4n63m3"; ``` **Lines 210–215** — the silent fallback: ```java /** * Returns the secret string used for authenticating the ZooKeeper peers. */ public String secret() { return firstNonNull(convertValue(secret, "replication.secret"), DEFAULT_SECRET); } ``` --- **File:** `server/src/main/java/com/linecorp/centraldogma/server/internal/replication/ZooKeeperCommandExecutor.java` **Lines 586–607** — JAAS wiring (same secret on both surfaces): ```java final String escapedSecret = jaasValueEscaper.escape(cfg.secret()); ImmutableList.of("Server", EmbeddedZooKeeper.SASL_SERVER_LOGIN_CONTEXT).forEach(name -> { buf.append(name).append(" {").append(newline); buf.append(DigestLoginModule.class.getName()).append(" required").append(newline); buf.append("user_super=\"").append(escapedSecret).append("\";").append(newline); buf.append("};").append(newline); }); ImmutableList.of("Client", EmbeddedZooKeeper.SASL_LEARNER_LOGIN_CONTEXT).forEach(name -> { buf.append(name).append(" {").append(newline); buf.append(DigestLoginModule.class.getName()).append(" required").append(newline); buf.append("username=\"super\"").append(newline); buf.append("password=\"").append(escapedSecret).append("\";").append(newline); buf.append("};").append(newline); }); ``` --- **File:** `server/src/main/java/com/linecorp/centraldogma/server/internal/replication/EmbeddedZooKeeper.java` **Line 44** — proves CD embeds the ZK server: ```java final class EmbeddedZooKeeper extends QuorumPeer { ``` **Lines 213–220** — client port binding (loopback only): ```java private static ServerCnxnFactory createCnxnFactory(QuorumPeerConfig zkCfg) throws IOException { final InetSocketAddress bindAddr = zkCfg.getClientPortAddress(); final ServerCnxnFactory cnxnFactory = ServerCnxnFactory.createFactory(); // Listen only on 127.0.0.1 because we do not want to expose ZooKeeper to others. cnxnFactory.configure(new InetSocketAddress("127.0.0.1", bindAddr != null ? bindAddr.getPort() : 0), zkCfg.getMaxClientCnxns()); return cnxnFactory; } ``` > Quorum/election ports are **NOT** loopback-bound — they bind to `replication.servers[].host` as configured, exposed on the inter-replica network. --- ## PoC Two attack surfaces, two scenarios. **Surface A** (client port, same-host) is implemented as a working read-only PoC. **Surface B** (quorum-port peer impersonation) is documented but intentionally not weaponized. ### Surface A — Same-Host Client Port (Loopback) PoC Python + kazoo + pure-sasl. Authenticates as `super` over SASL DIGEST-MD5 with the leaked secret and reads the full Central Dogma replication log. Hardcoded to `127.0.0.1`, read-only, prints first 5 entries. ```python #!/usr/bin/env python3 """ C3 PoC -- ZooKeeper default-secret takeover (read-only, loopback only). Demonstrates that a Central Dogma instance launched with a ZooKeeper-replicated configuration but without `replication.secret` set exposes its embedded ZooKeeper to anyone with local-host access, using the well-known credential `super / ch4n63m3`. SAFETY: * Hardcoded to 127.0.0.1. Refuses any other targ

Central Dogma versions before 0.78.0 contain an Open Redirect vulnerability that allows attackers to redirect users to untrusted sites via specially crafted URLs, potentially facilitating phishing attacks and credential theft.

Central Dogma versions prior to 0.64.1 is vulnerable to Cross-Site Scripting (XSS), which could allow for the leakage of user sessions and subsequent authentication bypass.