ghsa-g46h-2rq9-gw5m
Vulnerability from github
Summary
JSON objects after decoding might use more memory than their serialized version. It is possible to tune a JSON to maximize the factor between serialized memory usage and deserialized memory usage (similar to a zip bomb). While reproducing the issue, we could reach a factor of about 35. This can be used to circumvent the [max_request_size (https://openbao.org/docs/configuration/listener/tcp/) configuration parameter, which is meant to protect against Denial of Service attacks, and also makes Denial of Service attacks easier in general, as the attacker needs much less resources.
Details
The request body is parsed into a map[string]interface{} https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50 very early in the request handling chain (before authentication), which means an attacker can send a specifically crafted JSON object and cause an OOM crash. Additionally, for simpler requests with large numbers of strings, the audit subsystem can consume large quantities of CPU.
To remediate, set max_request_json_memory and max_request_json_strings.
Impact
- Unauthenticated Denial of Service
Resources
This issue was disclosed directly to HashiCorp and is the OpenBao equivalent of the following tickets:
- https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393
- https://nvd.nist.gov/vuln/detail/CVE-2025-6203
HashiCorp attributes the problem to the audit subsystem. For OpenBao, it was noted the problem was additionally in the requests handling logic.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.4.0"
},
"package": {
"ecosystem": "Go",
"name": "github.com/openbao/openbao"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.4.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-59043"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-17T17:08:11Z",
"nvd_published_at": "2025-10-17T16:15:38Z",
"severity": "HIGH"
},
"details": "### Summary\n\nJSON objects after decoding might use more memory than their serialized version. It is possible to tune a JSON to maximize the factor between serialized memory usage and deserialized memory usage (similar to a zip bomb). While reproducing the issue, we could reach a factor of about 35. This can be used to circumvent the [`max_request_size` (https://openbao.org/docs/configuration/listener/tcp/) configuration parameter, which is meant to protect against Denial of Service attacks, and also makes Denial of Service attacks easier in general, as the attacker needs much less resources.\n\n### Details\n\nThe request body is parsed into a `map[string]interface{}` https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50 very early in the request handling chain (before authentication), which means an attacker can send a specifically crafted JSON object and cause an OOM crash. Additionally, for simpler requests with large numbers of strings, the audit subsystem can consume large quantities of CPU. \n\nTo remediate, set `max_request_json_memory` and `max_request_json_strings`.\n\n### Impact\n\n- Unauthenticated Denial of Service\n\n### Resources\n\nThis issue was disclosed directly to HashiCorp and is the OpenBao equivalent of the following tickets:\n\n- https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393\n- https://nvd.nist.gov/vuln/detail/CVE-2025-6203\n\nHashiCorp attributes the problem to the audit subsystem. For OpenBao, it was noted the problem was additionally in the requests handling logic.",
"id": "GHSA-g46h-2rq9-gw5m",
"modified": "2025-10-17T19:07:55Z",
"published": "2025-10-17T17:08:11Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/openbao/openbao/security/advisories/GHSA-g46h-2rq9-gw5m"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59043"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-6203"
},
{
"type": "WEB",
"url": "https://github.com/openbao/openbao/pull/1756"
},
{
"type": "WEB",
"url": "https://github.com/openbao/openbao/commit/d418f238bc99adc72c73109faf574cc2b672880c"
},
{
"type": "WEB",
"url": "https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393"
},
{
"type": "PACKAGE",
"url": "https://github.com/openbao/openbao"
},
{
"type": "WEB",
"url": "https://github.com/openbao/openbao/blob/788536bd3e10818a7b4fb00aac6affc23388e5a9/http/logical.go#L50"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "OpenBao has potential Denial of Service vulnerability when processing malicious unauthenticated JSON requests"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.