CVE-2019-6493

Exp

SmartDefragDriver.sys (2.0) in IObit Smart Defrag 6 never frees an executable kernel pool that is allocated with user defined bytes and size when IOCTL 0x9C401CC0 is called. This kernel pointer can be leaked if the kernel pool becomes a "big" pool.

Published: 2019-04-11 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-6493 is rated Exploit Available (50.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.49%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2019-6493

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-6493

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 2026-06-15 0.14% 0.49% +0.35%
2 2025-03-30 0.83% 0.14% -0.69%
3 2025-03-29 — 0.83% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-6493

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.0 MEDIUM
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N 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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2019-6493

Affected software / configurations for CVE-2019-6493

Vendor Product Version Raw CPE
iobit smart_defrag 6 cpe:2.3:a:iobit:smart_defrag:6:*:*:*:*:*:*:*

References for CVE-2019-6493

URL Tags
https://downwithup.github.io/CVEPosts.html Exploit Vendor Advisory
https://www.iobit.com/en/iobitsmartdefrag.php Product Vendor Advisory
cvelogic Threat Intelligence