ghsa-4g74-7cff-xcv8
Vulnerability from github
Impact
youki utilizes bind mounting the container's /dev/null as a file mask. When performing this operation, the initial validation of the source /dev/null was insufficient. Specifically, we initially failed to verify whether /dev/null was genuinely present. However, we did perform validation to ensure that the /dev/null path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.
As a result, by replacing /dev/null with a symbolic link, we can bind-mount arbitrary files from the host system.
This is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems. https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2
Credits
Thanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings.
Also, @cyphar helped youki in finding the problem.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "youki"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.5.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-62161"
],
"database_specific": {
"cwe_ids": [
"CWE-363",
"CWE-61"
],
"github_reviewed": true,
"github_reviewed_at": "2025-11-05T18:44:18Z",
"nvd_published_at": "2025-11-06T00:15:36Z",
"severity": "HIGH"
},
"details": "### Impact ###\n\nyouki utilizes bind mounting the container\u0027s `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.\n\nAs a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system.\n\nThis is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems.\nhttps://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2\n\n### Credits\n\nThanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc\u0027s vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3\u0027s initial findings.\n\nAlso, @cyphar helped youki in finding the problem.",
"id": "GHSA-4g74-7cff-xcv8",
"modified": "2025-11-06T15:29:34Z",
"published": "2025-11-05T18:44:18Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2"
},
{
"type": "WEB",
"url": "https://github.com/youki-dev/youki/security/advisories/GHSA-4g74-7cff-xcv8"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-62161"
},
{
"type": "WEB",
"url": "https://github.com/youki-dev/youki/commit/5886c91073b9be748bd8d5aed49c4a820548030a"
},
{
"type": "PACKAGE",
"url": "https://github.com/youki-dev/youki"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
"type": "CVSS_V4"
}
],
"summary": "youki container escape via \"masked path\" abuse due to mount race conditions"
}
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.