Patchfirst
CVE-2022-24521 KEVRansomwarePublic exploit High · 7.8 EPSS 7.1%

Microsoft Windows CLFS Driver Privilege Escalation Vulnerability

Microsoft · Windows

Summary

The flaw is in the Common Log File System (CLFS) driver of Microsoft Windows, where improper validation of input leads to an out-of-bounds write. An attacker who already has low-privileged local access, with no user interaction required, can exploit it to elevate their privileges on the affected Windows system.

Official description · NVD

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Breakdown
77.3 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
5/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

  3. What can follow

First seen exploited 3 days before it was disclosed. Public exploit code (PoC-in-GitHub) appeared 4 years after disclosure.

  1. First seen exploitedVulnCheck KEV evidence3 days before
  2. Added to CISA KEVknown ransomware use; EU database agrees2 days before
  3. Disclosedday 0
  4. Public exploit codePoC-in-GitHub+4 yrs

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

3 , grouped by in kill-chain order 3

Initial AccessTA0001

Valid Accounts T1078 also Persistence, Privilege Escalation, Stealth
MITRE CTID mapping of the KEV entry · how it is exploited

This vulnerability is exploited by an attacker who has already obtained access to a target system to execute code. The vulnerability lies in the Common Log File System (CLFS) driver, specifically in the `CClfsBaseFilePersisted::LoadContainerQ()` function, due to a logic bug in handling container context objects. This vulnerability has been exploited by threat actors to gain elevated privileges on Windows systems. Attackers leveraged this flaw to execute arbitrary code with system-level privileges, allowing them to manipulate system processes and deploy additional malware to perform further malicious activities. The exploit in question is actively being used in the wild, primarily in ransomware campaigns. It involves corrupting the `pContainer` field of a container context object with a user-mode address by using malformed BLF files. Once the vulnerability is exploited, attackers can manipulate memory to execute code with elevated privileges. This allows them to achieve their objectives, such as stealing the System token and gaining full control over the compromised system.

ExecutionTA0002

MITRE CTID mapping of the KEV entry · follow-on activity

Privilege EscalationTA0004

MITRE CTID mapping of the KEV entry · primary impact

Detection

0 rules for this CVE · 182 general rules for its techniques

Rules for this CVE

0 that reference CVE-2022-24521 directly.

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What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

2 links, grouped by NVD tag (1 duplicate merged)
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