CVE-2024-4017 is a high severity improper privilege management flaw that allows DLL side-loading in the BeyondTrust U-Series Appliance on Windows, scored 8.8 by NVD. Versions from 3.4 before 4.0.3 are affected. Upgrade to U-Series Appliance software 4.0.3 or later.
What's affected
The record says the issue affects the BeyondTrust U-Series Appliance from version 3.4 before 4.0.3 on Windows, 64 bit. The fixed version is therefore 4.0.3, and the vendor's release notes for that version are linked in the record. This write-up did not fetch those notes, so read them for the full list of changes.
The affected area is the filesystem modules of the appliance software. The description says the improper privilege management allows DLL side-loading, which means a program can be made to load a malicious library from a place the attacker controls instead of the intended one.
The vector is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H: local access, low complexity, low privileges, changed scope. The KEV flag is false and the record reports no exploitation. A sibling CVE, CVE-2024-4018, was published the same day for the same product range.
The NVD record is dated 2024-04-19 and carries the vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H, a score of 8.8 (High). Weakness class: CWE-269.
How to check if you're exposed
Open the U-Series Appliance interface and read the software version, or check the version in your BeyondTrust administration console. Compare it with 4.0.3. Anything from 3.4 up to but not including 4.0.3 is in range.
The flaw needs local access with a low privilege account on the appliance's Windows host. List who can sign in locally to those systems, and who can run code on them. If the appliance sits in a locked down server segment with few interactive users, the practical exposure is smaller, but the version still needs to move.
If you manage many appliances, record the version of each so that the next advisory is quick to match.
What to do now
- List every U-Series Appliance and its software version.
- Upgrade each one from 3.4 up to before 4.0.3 to software 4.0.3 or later, following the vendor's upgrade notes.
- Remove local sign in rights from users who do not need them on the appliance host.
- Review local administrator group membership on those systems.
- Check the 4.0.3 release notes for other fixes and plan a regular update cadence.
Why it matters
The weakness is improper privilege management, CWE-269. DLL side-loading takes advantage of how Windows searches for libraries. If a privileged program looks in a location that a low privileged user can write to, a planted library runs with the program's rights.
The usual defences are to load libraries only from protected directories, to specify full paths, to sign and verify libraries, and to keep folder permissions tight. For defenders, the checklist is short: patch, and limit who can write to the application's directories.
Try it yourself
Click through it at your own pace, or open it full screen.
Quick check
Which version fixes CVE-2024-4017?
BeyondTrust U-Series Appliance software 4.0.3. The record says versions from 3.4 before 4.0.3 are affected.
Can this be exploited remotely?
The vector is local, so an attacker needs to run code or sign in on the host first.
Sources
Last reviewed: 19 October 2026.
