OCO-Server: Improper Certificate Validation
CVE-2026-114611 is a critical-severity improper certificate validation vulnerability in OCO-Server from Schorschii, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected OCO-Server versions: < 1.2.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of OCO-Server you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Schorschii | OCO-Server | < 1.2.3 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (github.com).
Official description
OCO-Server is a self-hosted endpoint management application for computer inventory, software deployment, and mobile device management. Prior to 1.2.3,the Apple MDM enrollment endpoint `frontend/api-mdm.php` verifies the signed enrollment-request plist with `openssl_pkcs7_verify(..., PKCS7_NOVERIFY, ...)`. `PKCS7_NOVERIFY` disables signer certificate chain and trust validation, so the signature only has to be self-consistent with whatever certificate is embedded in the PKCS#7 blob. A self-signed certificate from an unrelated attacker is accepted. Because the endpoint trusts the `SERIAL` field taken from the unverified payload, anyone who knows a registered device's serial number can sign a forged plist (`SERIAL` = victim device, attacker-chosen `UDID`) with an arbitrary self-signed certificate; POST it unauthenticated to `/api-mdm.php/profile` (Content-Type: `application/pkcs7-signature`); and receive the victim device's freshly minted MDM identity: a certificate with `CN=<serial>` issued by the server's internal MDM device CA, bundled with its private key in a PKCS#12 payload inside the returned `.mobileconfig` enrollment profile. Additionally, the victim's `mobile_device` database row is silently overwritten with the attacker-supplied `UDID` (device-record hijack). With the stolen certificate and key, the attacker can impersonate the victim device on all subsequent MDM traffic (`/checkin`, `/mdm`, `/parameters`), which authenticate callers by the certificate CN (the serial number) via `checkSignature()` in the same file. This yields control over the victim device's MDM relationship: reading its management data, replacing its push token, and disrupting or redirecting its enrollment. Version 1.2.3 fixes the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in OCO-Server
- 7.4 High severity
Recent Improper Certificate Validation vulnerabilities
- 9.1 Critical severity
- 8.7 High severity
- 10.0 Critical severity
- 10.0 Critical severity
- 8.8 High severity
- 9.1 Critical severity
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