CVE-2015-7874 – CVE-2015-7874 is a buffer overflow vulnerabilit... (How to Fix)

📋 TL;DR

CVE-2015-7874 is a buffer overflow vulnerability in KiTTY Portable's chat server that allows remote attackers to execute arbitrary code by sending a specially crafted long nickname. This affects KiTTY Portable 0.65.0.2p and earlier versions. Attackers can potentially gain full control of affected systems.

💻 Affected Systems

Products:

KiTTY Portable

Versions: 0.65.0.2p and earlier

Operating Systems: Windows, Linux, macOS (via portable versions)

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems running the KiTTY chat server feature. Standard SSH functionality may not be affected.

📦 What is this software?

Kitty Portable by Portapps

View all CVEs affecting Kitty Portable →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, and persistent backdoor installation

🟠

Likely Case

Remote code execution allowing attackers to run arbitrary commands with the privileges of the KiTTY process

🟢

If Mitigated

Denial of service if exploit fails or system crashes without code execution

🌐 Internet-Facing: HIGH - The chat server can be exposed to internet connections, making it directly accessible to attackers

🏢 Internal Only: MEDIUM - Internal network exposure still presents risk from insider threats or compromised internal systems

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: CONFIRMED

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploit code is publicly available and requires no authentication. Simple buffer overflow with predictable exploitation.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: KiTTY Portable 0.65.0.3p and later

Vendor Advisory: https://www.9bis.net/kitty/

Restart Required: Yes

Instructions:

1. Download latest KiTTY Portable version from official website
2. Replace existing installation with new version
3. Restart any running KiTTY instances

🔧 Temporary Workarounds

Disable Chat Server

all

Disable the vulnerable chat server feature in KiTTY configuration

Edit kitty.ini and set 'ChatServer=0' or remove chat server configuration

Network Segmentation

all

Block network access to KiTTY chat server ports

firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="0.0.0.0/0" port port="<chat-port>" protocol="tcp" reject'
netsh advfirewall firewall add rule name="Block KiTTY Chat" dir=in action=block protocol=TCP localport=<chat-port>

🧯 If You Can't Patch

Disable the chat server feature entirely in KiTTY configuration
Implement network segmentation to isolate systems running vulnerable KiTTY versions

🔍 How to Verify

Check if Vulnerable:

Check KiTTY version: Open KiTTY, go to Help > About, verify version is 0.65.0.2p or earlier

Check Version:

On Windows: kitty.exe --version (if supported) or check Help > About GUI

Verify Fix Applied:

Update to version 0.65.0.3p or later and verify version in Help > About

📡 Detection & Monitoring

Log Indicators:

Unusual process creation from KiTTY
Chat server crash logs
Network connections to unusual ports from KiTTY

Network Indicators:

Large nickname strings sent to KiTTY chat server port
Unexpected network traffic to KiTTY chat ports

SIEM Query:

process_name:"kitty.exe" AND (event_type:"process_creation" OR event_type:"crash")

📊 Metadata

CVE ID: CVE-2015-7874

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-120

Published: January 15, 2020

Last Updated: November 21, 2024

🔗 References

https://www.exploit-db.com/exploits/39119/ Exploit,Third Party Advisory,VDB Entry
https://www.exploit-db.com/exploits/39119/ Exploit,Third Party Advisory,VDB Entry

📤 Share & Export

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🔗 Related Vulnerabilities

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