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Fencer Vulns
high 8.8

CVE-2023-43633 json

Debug Functions Unlockable Without Triggering Measured Boot

published 2023-09-21 3 y ago modified 2026-06-17 4 mo ago also GHSA-4c4v-42hc-72p6 , GO-2026-4428 , EUVD-2023-48033

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

On boot, the Pillar eve container checks for the existence and content of “/config/GlobalConfig/global.json”.

If the file exists, it overrides the existing configuration on the device on boot.

This allows an attacker to change the system’s configuration, which also includes some debug functions.

This could be used to unlock the ssh with custom “authorized_keys” via the “debug.enable.ssh” key, similar to the “authorized_keys” finding that was noted before.

Other usages include unlocking the usb to enable the keyboard via the “debug.enable.usb” key, allowing VNC access via the “app.allow.vnc” key, and more.

An attacker could easily enable these debug functionalities 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, thereby 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.

Patch / fix

  • go github.com/lf-edge/eve 0.0.0-20220708121648-5fef4d92e758
  • LF-Edge, Zededa EVE OS 8.6.0, 9.5.0
  • lfedge eve 8.6.0, 9.5.0
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260205T172317-150000.1.146.1

suse advisories SUSE-SU-2026:0403-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 5.9 CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/lf-edge/eve
<0.0.0-20220708121648-5fef4d92e758
0.0.0-20220708121648-5fef4d92e758

Affected products

  • LF-Edge, Zededa EVE OS
  • lfedge eve

Classification

Weakness
  • CWE-522 Insufficiently Protected Credentials
  • CWE-922 Insecure Storage of Sensitive Information

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.