CVE-2026-55548

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, the PacketsApi.exportPackets endpoint in yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java failed to enforce object-level ReadPacket privileges when a request omitted specific packet names: with an empty name list the ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet) call passed over an empty set, no WHERE pname IN filter was applied to the resulting SELECT * FROM tm query, and the onTuple handler streamed every retrieved packet without any per-row authorization check, so a low-privileged or zero-privilege authenticated user could dump the entire raw telemetry packet archive and bypass the role-based access control model. This issue is fixed in versions 5.12.8 and 5.13.2, which enforce per-packet ReadPacket checks in exportPackets.

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, the PacketsApi.exportPackets endpoint in yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java failed to enforce object-level ReadPacket privileges when a request omitted specific packet names: with an empty name list the ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet) call passed over an empty set, no WHERE pname IN filter was applied to the resulting SELECT * FROM tm query, and the onTuple handler streamed every retrieved packet without any per-row authorization check, so a low-privileged or zero-privilege authenticated user could dump the entire raw telemetry packet archive and bypass the role-based access control model. This issue is fixed in versions 5.12.8 and 5.13.2, which enforce per-packet ReadPacket checks in exportPackets.

Summary

The PacketsApi.exportPackets endpoint in Yamcs fails to properly enforce object-level privileges (ReadPacket) when an API request omits specific packet names. As a result, an attacker with a low-privileged account (or any authenticated user with zero privileges) can dump the entire archive of raw telemetry packets for a Yamcs instance. This leads to a massive Information Disclosure of sensitive mission telemetry, completely bypassing the intended Role-Based Access Control (RBAC) model.

Vulnerability Details

In yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java, the exportPackets method processes requests to export raw packets from the tm (telemetry archive) table.

    @Override
    public void exportPackets(Context ctx, ExportPacketsRequest request, Observer<HttpBody> observer) {
        String instance = InstancesApi.verifyInstance(request.getInstance());

        Set<String> nameSet = new HashSet<>(request.getNameList());
        ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet);

        SqlBuilder sqlb = new SqlBuilder(XtceTmRecorder.TABLE_NAME);
        
        // ... time filters ...

        if (request.getNameCount() > 0) {
            sqlb.whereColIn("pname", nameSet);
        }
        String sql = sqlb.toString();
        // ...

The method attempts to verify privileges using ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet). However, if the request.getNameList() is empty (i.e., the attacker does not specify any packet names to filter by), nameSet is empty. The checkObjectPrivileges method loops over this empty set and successfully passes without throwing a ForbiddenException.

Since request.getNameCount() is 0, no WHERE pname IN (...) filter is added to the SQL query. The resulting sql query becomes a SELECT * FROM tm (with optional time filters).

Finally, the query is executed and the results are streamed back to the user:

        StreamFactory.stream(instance, sql, sqlb.getQueryArguments(), new StreamSubscriber() {

            @Override
            public void onTuple(Stream stream, Tuple tuple) {
                if (observer.isCancelled()) {
                    stream.close();
                    return;
                }

                byte[] raw = (byte[]) tuple.getColumn(StandardTupleDefinitions.TM_PACKET_COLUMN);
                HttpBody body = HttpBody.newBuilder()
                        .setData(ByteString.copyFrom(raw))
                        .build();
                observer.next(body);
            }
            // ...

Crucially, unlike the streamPackets or exportPacket methods (which explicitly check ctx.user.hasObjectPrivilege for each packet retrieved before returning them), the onTuple handler in exportPackets blindly streams all retrieved packets to the user without any per-row authorization checks.

Thus, a user who possesses no ReadPacket privileges at all can easily bypass authorization and extract all telemetry data from the archive.

Steps to Reproduce

1. Start the Yamcs server (e.g., using the simulation example) with authentication enforced.
2. Log in as a low-privileged user (or use their credentials) who does not have the ReadPacket privilege.
3. Send an HTTP GET request to the export packets endpoint without specifying any name parameters:

   curl -v -u low_priv_user:password "http://localhost:8090/api/archive/simulator:exportPackets" -o dumped_packets.raw
   

4. Observe that the server responds with HTTP 200 OK and streams all raw packets to the response, saving them to dumped_packets.raw.
5. The downloaded file contains raw CCSDS Space Packets (binary telemetry data).
6. Contrast this with an attempt to fetch a specific packet (or calling listPackets for an unauthorized packet), which correctly enforces authorization and rejects the request.

Impact

Telemetry packets contain the core mission data, vehicle health…

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, the PacketsApi.exportPackets endpoint in yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java failed to enforce object-level ReadPacket privileges when a request omitted specific packet names: with an empty name list the ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet) call passed over an empty set, no WHERE pname IN filter was applied to the resulting SELECT * FROM tm query, and the onTuple handler streamed every retrieved packet without any per-row authorization check, so a low-privileged or zero-privilege authenticated user could dump the entire raw telemetry packet archive and bypass the role-based access control model. This issue is fixed in versions 5.12.8 and 5.13.2, which enforce per-packet ReadPacket checks in exportPackets.

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, the PacketsApi.exportPackets endpoint in yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java failed to enforce object-level ReadPacket privileges when a request omitted specific packet names: with an empty name list the ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet) call passed over an empty set, no WHERE pname IN filter was applied to the resulting SELECT * FROM tm query, and the onTuple handler streamed every retrieved packet without any per-row authorization check, so a low-privileged or zero-privilege authenticated user could dump the entire raw telemetry packet archive and bypass the role-based access control model. This issue is fixed in versions 5.12.8 and 5.13.2, which enforce per-packet ReadPacket checks in exportPackets.

Summary

The PacketsApi.exportPackets endpoint in Yamcs fails to properly enforce object-level privileges (ReadPacket) when an API request omits specific packet names. As a result, an attacker with a low-privileged account (or any authenticated user with zero privileges) can dump the entire archive of raw telemetry packets for a Yamcs instance. This leads to a massive Information Disclosure of sensitive mission telemetry, completely bypassing the intended Role-Based Access Control (RBAC) model.

Vulnerability Details

In yamcs-core/src/main/java/org/yamcs/http/api/PacketsApi.java, the exportPackets method processes requests to export raw packets from the tm (telemetry archive) table.

    @Override
    public void exportPackets(Context ctx, ExportPacketsRequest request, Observer<HttpBody> observer) {
        String instance = InstancesApi.verifyInstance(request.getInstance());

        Set<String> nameSet = new HashSet<>(request.getNameList());
        ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet);

        SqlBuilder sqlb = new SqlBuilder(XtceTmRecorder.TABLE_NAME);
        
        // ... time filters ...

        if (request.getNameCount() > 0) {
            sqlb.whereColIn("pname", nameSet);
        }
        String sql = sqlb.toString();
        // ...

The method attempts to verify privileges using ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet). However, if the request.getNameList() is empty (i.e., the attacker does not specify any packet names to filter by), nameSet is empty. The checkObjectPrivileges method loops over this empty set and successfully passes without throwing a ForbiddenException.

Since request.getNameCount() is 0, no WHERE pname IN (...) filter is added to the SQL query. The resulting sql query becomes a SELECT * FROM tm (with optional time filters).

Finally, the query is executed and the results are streamed back to the user:

        StreamFactory.stream(instance, sql, sqlb.getQueryArguments(), new StreamSubscriber() {

            @Override
            public void onTuple(Stream stream, Tuple tuple) {
                if (observer.isCancelled()) {
                    stream.close();
                    return;
                }

                byte[] raw = (byte[]) tuple.getColumn(StandardTupleDefinitions.TM_PACKET_COLUMN);
                HttpBody body = HttpBody.newBuilder()
                        .setData(ByteString.copyFrom(raw))
                        .build();
                observer.next(body);
            }
            // ...

Crucially, unlike the streamPackets or exportPacket methods (which explicitly check ctx.user.hasObjectPrivilege for each packet retrieved before returning them), the onTuple handler in exportPackets blindly streams all retrieved packets to the user without any per-row authorization checks.

Thus, a user who possesses no ReadPacket privileges at all can easily bypass authorization and extract all telemetry data from the archive.

Steps to Reproduce

1. Start the Yamcs server (e.g., using the simulation example) with authentication enforced.
2. Log in as a low-privileged user (or use their credentials) who does not have the ReadPacket privilege.
3. Send an HTTP GET request to the export packets endpoint without specifying any name parameters:

   curl -v -u low_priv_user:password "http://localhost:8090/api/archive/simulator:exportPackets" -o dumped_packets.raw
   

4. Observe that the server responds with HTTP 200 OK and streams all raw packets to the response, saving them to dumped_packets.raw.
5. The downloaded file contains raw CCSDS Space Packets (binary telemetry data).
6. Contrast this with an attempt to fetch a specific packet (or calling listPackets for an unauthorized packet), which correctly enforces authorization and rejects the request.

Impact

Telemetry packets contain the core mission data, vehicle health…