GHSA-8XJQ-PR36-CCGF
Vulnerability from github – Published: 2026-08-28 17:15 – Updated: 2026-08-28 17:15
VLAI
Summary
Yamcs: Insecure Direct Object Reference (IDOR) in PacketsApi allows unprivileged users to dump all telemetry packets
Details
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
- Start the Yamcs server (e.g., using the
simulationexample) with authentication enforced. - Log in as a low-privileged user (or use their credentials) who does not have the
ReadPacketprivilege. - Send an HTTP GET request to the export packets endpoint without specifying any
nameparameters:bash curl -v -u low_priv_user:password "http://localhost:8090/api/archive/simulator:exportPackets" -o dumped_packets.raw - Observe that the server responds with HTTP
200 OKand streams all raw packets to the response, saving them todumped_packets.raw. - The downloaded file contains raw CCSDS Space Packets (binary telemetry data).
- Contrast this with an attempt to fetch a specific packet (or calling
listPacketsfor an unauthorized packet), which correctly enforces authorization and rejects the request.
Impact
Telemetry packets contain the core mission data, vehicle health status, and sensitive measurements (CCSDS Protocol data). This vulnerability completely breaks the access control model for telemetry data, allowing any authenticated user to exfiltrate all historical telemetry packets from the database. In an aerospace or mission-critical environment, this represents a severe data leak (Massive Information Disclosure) of proprietary or classified spacecraft data.
Remediation
Ensure that exportPackets enforces the same per-row privilege checks as streamPackets.
Update the onTuple handler to check the user's privileges before emitting each packet:
@Override
public void onTuple(Stream stream, Tuple tuple) {
if (observer.isCancelled()) {
stream.close();
return;
}
// FIX: Retrieve packet name and check authorization
String pname = (String) tuple.getColumn(XtceTmRecorder.PNAME_COLUMN);
if (ctx.user.hasObjectPrivilege(ObjectPrivilegeType.ReadPacket, pname)) {
byte[] raw = (byte[]) tuple.getColumn(StandardTupleDefinitions.TM_PACKET_COLUMN);
HttpBody body = HttpBody.newBuilder()
.setData(ByteString.copyFrom(raw))
.build();
observer.next(body);
}
}
System Information
- Affected Versions: 5.13.0 (Latest Release), 5.12.x, and current
masterbranch. - Tested Revision (master):
309218c651680f79df11a8d0f8628f7033f98a83 - Vulnerability Type: Insecure Direct Object Reference (IDOR) / Logical Authorization Bypass
PoC Images:
-
Check version:
-
Check privilege of user:
-
Exploit:
Severity
4.3 (Medium)
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.13.1"
},
"package": {
"ecosystem": "Maven",
"name": "org.yamcs:yamcs-core"
},
"ranges": [
{
"events": [
{
"introduced": "5.13.0"
},
{
"fixed": "5.13.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.12.7"
},
"package": {
"ecosystem": "Maven",
"name": "org.yamcs:yamcs-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.12.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-55548"
],
"database_specific": {
"cwe_ids": [
"CWE-284",
"CWE-862"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-28T17:15:01Z",
"nvd_published_at": "2026-07-16T17:16:57Z",
"severity": "MODERATE"
},
"details": "## Summary\nThe `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.\n\n## Vulnerability Details\nIn `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.\n\n```java\n @Override\n public void exportPackets(Context ctx, ExportPacketsRequest request, Observer\u003cHttpBody\u003e observer) {\n String instance = InstancesApi.verifyInstance(request.getInstance());\n\n Set\u003cString\u003e nameSet = new HashSet\u003c\u003e(request.getNameList());\n ctx.checkObjectPrivileges(ObjectPrivilegeType.ReadPacket, nameSet);\n\n SqlBuilder sqlb = new SqlBuilder(XtceTmRecorder.TABLE_NAME);\n \n // ... time filters ...\n\n if (request.getNameCount() \u003e 0) {\n sqlb.whereColIn(\"pname\", nameSet);\n }\n String sql = sqlb.toString();\n // ...\n```\nThe 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`. \n\nSince `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).\n\nFinally, the query is executed and the results are streamed back to the user:\n```java\n StreamFactory.stream(instance, sql, sqlb.getQueryArguments(), new StreamSubscriber() {\n\n @Override\n public void onTuple(Stream stream, Tuple tuple) {\n if (observer.isCancelled()) {\n stream.close();\n return;\n }\n\n byte[] raw = (byte[]) tuple.getColumn(StandardTupleDefinitions.TM_PACKET_COLUMN);\n HttpBody body = HttpBody.newBuilder()\n .setData(ByteString.copyFrom(raw))\n .build();\n observer.next(body);\n }\n // ...\n```\nCrucially, 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**. \n\nThus, a user who possesses no `ReadPacket` privileges at all can easily bypass authorization and extract all telemetry data from the archive.\n\n## Steps to Reproduce\n1. Start the Yamcs server (e.g., using the `simulation` example) with authentication enforced.\n2. Log in as a low-privileged user (or use their credentials) who does **not** have the `ReadPacket` privilege.\n3. Send an HTTP GET request to the export packets endpoint without specifying any `name` parameters:\n ```bash\n curl -v -u low_priv_user:password \"http://localhost:8090/api/archive/simulator:exportPackets\" -o dumped_packets.raw\n ```\n4. Observe that the server responds with HTTP `200 OK` and streams all raw packets to the response, saving them to `dumped_packets.raw`. \n5. The downloaded file contains raw CCSDS Space Packets (binary telemetry data).\n6. 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.\n\n## Impact\nTelemetry packets contain the core mission data, vehicle health status, and sensitive measurements (CCSDS Protocol data). This vulnerability completely breaks the access control model for telemetry data, allowing any authenticated user to exfiltrate all historical telemetry packets from the database. In an aerospace or mission-critical environment, this represents a severe data leak (Massive Information Disclosure) of proprietary or classified spacecraft data.\n\n## Remediation\nEnsure that `exportPackets` enforces the same per-row privilege checks as `streamPackets`. \nUpdate the `onTuple` handler to check the user\u0027s privileges before emitting each packet:\n\n```java\n @Override\n public void onTuple(Stream stream, Tuple tuple) {\n if (observer.isCancelled()) {\n stream.close();\n return;\n }\n\n // FIX: Retrieve packet name and check authorization\n String pname = (String) tuple.getColumn(XtceTmRecorder.PNAME_COLUMN);\n if (ctx.user.hasObjectPrivilege(ObjectPrivilegeType.ReadPacket, pname)) {\n byte[] raw = (byte[]) tuple.getColumn(StandardTupleDefinitions.TM_PACKET_COLUMN);\n HttpBody body = HttpBody.newBuilder()\n .setData(ByteString.copyFrom(raw))\n .build();\n observer.next(body);\n }\n }\n```\n\n## System Information\n- **Affected Versions:** 5.13.0 (Latest Release), 5.12.x, and current `master` branch.\n- **Tested Revision (master):** `309218c651680f79df11a8d0f8628f7033f98a83` \n- **Vulnerability Type:** Insecure Direct Object Reference (IDOR) / Logical Authorization Bypass\n\n## PoC Images:\n\n- Check version:\n\u003cimg width=\"1157\" height=\"489\" alt=\"image\" src=\"https://github.com/user-attachments/assets/58608222-b76f-4eb4-8e57-423523062992\" /\u003e\n\n- Check privilege of user:\n\u003cimg width=\"1439\" height=\"953\" alt=\"image\" src=\"https://github.com/user-attachments/assets/aa7e55f2-2460-4f24-8b6f-d461d2499a6f\" /\u003e\n\u003cimg width=\"1214\" height=\"224\" alt=\"image\" src=\"https://github.com/user-attachments/assets/e9123ae3-a194-462d-a5ca-2c0b1cc9cc6f\" /\u003e\n\n\n- Exploit:\n\n\n\u003cimg width=\"1728\" height=\"685\" alt=\"image\" src=\"https://github.com/user-attachments/assets/0c7b3099-44d6-4392-bbaa-8e84cc151784\" /\u003e\n\n\u003cimg width=\"1768\" height=\"797\" alt=\"image\" src=\"https://github.com/user-attachments/assets/df4016a5-d460-4611-a34a-8c0d206edd9c\" /\u003e",
"id": "GHSA-8xjq-pr36-ccgf",
"modified": "2026-08-28T17:15:02Z",
"published": "2026-08-28T17:15:01Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-8xjq-pr36-ccgf"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55548"
},
{
"type": "WEB",
"url": "https://github.com/yamcs/yamcs/commit/b566beceba98cc35514b0e1519be126b8c5a0438"
},
{
"type": "WEB",
"url": "https://github.com/yamcs/yamcs/commit/c743cc3acf5b5c53ff5181b94eacc21340f70dd9"
},
{
"type": "PACKAGE",
"url": "https://github.com/yamcs/yamcs"
},
{
"type": "WEB",
"url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8"
},
{
"type": "WEB",
"url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "Yamcs: Insecure Direct Object Reference (IDOR) in PacketsApi allows unprivileged users to dump all telemetry packets"
}
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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