GHSA-F6WP-8J9R-FRRG
Vulnerability from github – Published: 2023-09-21 15:30 – Updated: 2024-04-04 07:47On boot, the Pillar eve container checks for the existence and content of “/config/authorized_keys”.
If the file is present, and contains a supported public key, the container will go on to open port 22 and enable sshd with the given keys as the authorized keys for root login.
An attacker could easily add their own keys and gain full control over the system without triggering the “measured boot” mechanism implemented by EVE OS, and without marking the device as “UUD” (“Unknown Update Detected”).
This is because the “/config” partition is not protected by “measured boot”, it is mutable, and it is not encrypted in any way.
An attacker can gain full control over the device without changing the PCR values, thus not triggering the “measured boot” mechanism, and having full access to the vault.
Note:
This issue was partially fixed in these commits (after disclosure to Zededa), where the config partition measurement was added to PCR13:
• aa3501d6c57206ced222c33aea15a9169d629141
• 5fef4d92e75838cc78010edaed5247dfbdae1889.
This issue was made viable in version 9.0.0 when the calculation was moved to PCR14 but it was not included in the measured boot.
{
"affected": [],
"aliases": [
"CVE-2023-43631"
],
"database_specific": {
"cwe_ids": [
"CWE-522"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-09-21T14:15:10Z",
"severity": "HIGH"
},
"details": "\nOn boot, the Pillar eve container checks for the existence and content of\n\u201c/config/authorized_keys\u201d.\n\nIf the file is present, and contains a supported public key, the container will go on to open\nport 22 and enable sshd with the given keys as the authorized keys for root login.\n\nAn attacker could easily add their own keys and gain full control over the system without\ntriggering the \u201cmeasured boot\u201d mechanism implemented by EVE OS, and without marking\nthe device as \u201cUUD\u201d (\u201cUnknown Update Detected\u201d).\n\nThis is because the \u201c/config\u201d partition is not protected by \u201cmeasured boot\u201d, it is mutable, and\nit is not encrypted in any way.\n\n\n\n\nAn attacker can gain full control over the device without changing the PCR values, thus not\ntriggering the \u201cmeasured boot\u201d mechanism, and having full access to the vault.\n\n\n\nNote:\n\nThis issue was partially fixed in these commits (after disclosure to Zededa), where the config\npartition measurement was added to PCR13:\n\n\u2022 aa3501d6c57206ced222c33aea15a9169d629141\n\n\u2022 5fef4d92e75838cc78010edaed5247dfbdae1889.\n\nThis issue was made viable in version 9.0.0 when the calculation was moved to PCR14 but it was not included in the measured boot.",
"id": "GHSA-f6wp-8j9r-frrg",
"modified": "2024-04-04T07:47:41Z",
"published": "2023-09-21T15:30:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-43631"
},
{
"type": "WEB",
"url": "https://asrg.io/security-advisories/cve-2023-43631"
},
{
"type": "WEB",
"url": "https://asrg.io/security-advisories/ssh-as-root-unlockable-without-triggering-measured-boot"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.