Notepad++ Privilege Escalation in Installer via Uncontrolled Executable Search Path

Notepad++ is a free and open-source source code editor. In versions 8.8.1 and prior, a privilege escalation vulnerability exists in the Notepad++ v8.8.1 installer that allows unprivileged users to gain SYSTEM-level privileges through insecure executable search paths. An attacker could use social engineering or clickjacking to trick users into downloading both the legitimate installer and a malicious executable to the same directory (typically Downloads folder - which is known as Vulnerable directory). Upon running the installer, the attack executes automatically with SYSTEM privileges. This issue has been fixed and will be released in version 8.8.2.

Notepad++ 8.9.3 Format String Injection via nativeLang.xml

Notepad++ 8.9.3 contains a format string injection vulnerability in the Find Results panel handler that allows attackers to cause denial of service and information disclosure by crafting a malicious nativeLang.xml language pack file. Attackers can distribute a poisoned language pack through community channels that triggers format string interpretation when a user performs search operations, leading to access violations and potential leakage of stack or register contents.

Stack-Based Buffer Overflow in Notepad++ File Drop Handler leads to DoS

A stack-based buffer overflow vulnerability exists in Notepad++ version 8.9.3 in the file drop handler component. When a user drags and drops a directory path of exactly 259 characters without a trailing backslash, the application appends a backslash and null terminator without proper bounds checking, resulting in a stack buffer overflow and application crash (STATUS_STACK_BUFFER_OVERRUN).

Vulnerability in Notepad++

Successful exploitation of the string injection vulnerability could allow an attacker to obtain memory address information or crash the application.

Notepad++ v8.8.3 has a DLL hijacking vulnerability, which can replace the original DLL file to execute malicious code. NOTE: this is disputed by multiple parties because the behavior only occurs when a user installs the product into a directory tree that allows write access by arbitrary unprivileged users.

Notepad++ < 8.8.9 WinGUp Updater Lacks Update Integrity Verification

Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges of the user.