CVE-2025-24985: Microsoft Windows Fast FAT File System Driver Integer Overflow Vulnerability
Affects Microsoft WindowsSource CISA KEV
Exploited in the wild · KEV due 1 Apr 2025 · 3% EPSS : apply the vendor's fix or mitigations to Microsoft Windows now.
Data as of 10/24/2026, 22:16:00 UTC
- Exploitation
Actively exploited – in CISA KEV since 03/11/2025
- KEV deadline
- 04/01/2025 US federal agencies must patch by this date; a sensible deadline for everyone else.
- EPSS
- 3.8% chance of exploitation in 30 days – higher than 90% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:CWhat to do
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description
Microsoft Windows Fast FAT File System Driver contains an integer overflow or wraparound vulnerability that allows an unauthorized attacker to execute code locally.
Weaknesses
- CWE-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
- CWE-122Heap-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #16
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().