CVE-2019-1121

HIGH

Windows 10 and Windows Server 2016/2019 - Remote Code Execution in DirectWrite

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2019-1121. PoCs published by Google Security Research.

AI-analyzed exploit summary This exploit demonstrates a heap-buffer-overflow vulnerability in AFDKO's CFF Reader module due to improper bounds checking of the iFD field in the FDSelect table. The PoC triggers an out-of-bounds access in h->fdicts.array, leading to a crash detectable by AddressSanitizer.

Description

A remote code execution vulnerability exists in the way that DirectWrite handles objects in memory, aka 'DirectWrite Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2019-1117, CVE-2019-1118, CVE-2019-1119, CVE-2019-1120, CVE-2019-1122, CVE-2019-1123, CVE-2019-1124, CVE-2019-1127, CVE-2019-1128.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Google Security Research · textdoswindows
https://www.exploit-db.com/exploits/47097

This exploit demonstrates a heap-buffer-overflow vulnerability in AFDKO's CFF Reader module due to improper bounds checking of the iFD field in the FDSelect table. The PoC triggers an out-of-bounds access in h->fdicts.array, leading to a crash detectable by AddressSanitizer.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: AFDKO (Adobe Font Development Kit for OpenType) and Microsoft DirectWrite (Windows 10 1709+)
No auth needed
Prerequisites: A specially crafted OpenType font file with a modified FDSelect table · User interaction (e.g., printing a webpage with the malicious font in Microsoft Edge)
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 8.8
EPSS 0.1694
EPSS Percentile 96.7%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

Status published
Products (7)
microsoft/windows_10 1709
microsoft/windows_10 1803
microsoft/windows_10 1809
microsoft/windows_10 1903
microsoft/windows_server_2016 1803
microsoft/windows_server_2016 1903
microsoft/windows_server_2019
Published Jul 15, 2019
Tracked Since Feb 18, 2026