CVE-2017-12840

A kernel driver, namely DLMFENC.sys, bundled with the DESLock+ client application 4.8.16 and earlier contains a locally exploitable heap based buffer overflow in the handling of an IOCTL message of type 0x0FA4204. The vulnerability is present due to the kernel driver failing to allocate sufficient memory on the kernel heap to contain a user supplied string as such the string is copied into a buffer of constant size (0x1000-bytes) and thus an overflow condition results. Access to the kernel driver is permitted through an obfuscated interface whereby bytes of user supplied message are "authenticated" via an obfuscation routine employing a linear equation.

Published: 2017-08-28 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-12840 is rated Low Risk (36.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-12840

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.22% 0.06% -0.16%
2 2025-03-29 0.06% 0.22% +0.16%
3 2025-03-17 — 0.06% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-12840

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.0 HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2017-12840

Affected software / configurations for CVE-2017-12840

Vendor Product Version Raw CPE
deslock deslock\+ <= 4.8.16 cpe:2.3:a:deslock:deslock\+:*:*:*:*:*:*:*:*

References for CVE-2017-12840

cvelogic Threat Intelligence