SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-31727

Incorrect access control in zam64.sys, zam32.sys in MalwareFox AntiMalware 2.74.0.150 where IOCTL's 0x80002014, 0x80002018 expose unrestricted disk read/write capabilities respectively.

HIGH 7.8EPSS 0.37%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.37%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Incorrect access control in zam64.sys, zam32.sys in MalwareFox AntiMalware 2.74.0.150 where IOCTL's 0x80002014, 0x80002018 expose unrestricted disk read/write capabilities respectively. A non-privileged process can open a handle to \.\ZemanaAntiMalware, register with the driver using IOCTL 0x80002010 and send these IOCTL's to escalate privileges by overwriting the boot sector or overwriting critical code in the pagefile.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.37% probability · 31th percentile
CISA KEV
Not listed
Affected
malwarefox/antimalware
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.