CVE-2019-9896

HIGH

PuTTY < 0.71 - Uncontrolled Search Path Element via Help File

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2019-9896. PoCs published by yasinyilmaz.

AI-analyzed exploit summary This PoC demonstrates a CHM hijacking vulnerability in PuTTY up to version 0.70, where a malicious CHM file can execute arbitrary code via embedded HTML objects and JavaScript. The exploit leverages HTML Help Workshop to create a malicious CHM file that spawns a reverse shell when opened.

Description

In PuTTY versions before 0.71 on Windows, local attackers could hijack the application by putting a malicious help file in the same directory as the executable.

Exploits (1)

nomisec WORKING POC 7 stars
by yasinyilmaz · poc
https://github.com/yasinyilmaz/vuln-chm-hijack

This PoC demonstrates a CHM hijacking vulnerability in PuTTY up to version 0.70, where a malicious CHM file can execute arbitrary code via embedded HTML objects and JavaScript. The exploit leverages HTML Help Workshop to create a malicious CHM file that spawns a reverse shell when opened.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: PuTTY up to version 0.70
No auth needed
Prerequisites: HTML Help Workshop · Ability to place malicious CHM file in PuTTY's execution directory
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Release Notes, Third Party Advisory x_refsource_misc
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
Mailing List, Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00004.html
Mailing List, Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00020.html
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20190404-0001/

Scores

CVSS v3 7.8
EPSS 0.0216
EPSS Percentile 84.5%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-427
Status published
Products (3)
opensuse/backports_sle 15.0
opensuse/leap 15.0
putty/putty < 0.71
Published Mar 21, 2019
Tracked Since Feb 18, 2026