55%
18%
60%
Netty is an open-source, asynchronous event-driven network application framework. The package `io.netty:netty-codec-http` prior to version 4.1.77.Final contains an insufficient fix for CVE-2021-21290. When Netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled. This only impacts applications running on Java version 6 and lower. Additionally, this vulnerability impacts code running on Unix-like systems, and very old versions of Mac OSX and Windows as they all share the system temporary directory between all users. Version 4.1.77.Final contains a patch for this vulnerability. As a workaround, specify one's own `java.io.tmpdir` when starting the JVM or use DefaultHttpDataFactory.setBaseDir(...) to set the directory to something that is only readable by the current user.
CVSS 3.1 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).
CVSS 2.0 Base Score 1.9. CVSS Attack Vector: local. CVSS Attack Complexity: medium. CVSS Vector: (AV:L/AC:M/Au:N/C:P/I:N/A:N).
In the following code examples a temporary file is created and written to and after using the temporary file the file is closed and deleted from the file system.
rmtmp();
return (-1);// write data to tmp fileHowever, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.
}out.close();Similarly, the createTempFile() method used in the Java code creates a temp file that may be readable and writable to all users.
Additionally both methods used above place the file into a default directory. On UNIX systems the default directory is usually "/tmp" or "/var/tmp" and on Windows systems the default directory is usually "C:\\Windows\\Temp", which may be easily accessible to attackers, possibly enabling them to read and modify the contents of the temp file.
In the following code examples a temporary file is created and written to and after using the temporary file the file is closed and deleted from the file system.
rmtmp();
return (-1);// write data to tmp fileHowever, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.
}out.close();Similarly, the createTempFile() method used in the Java code creates a temp file that may be readable and writable to all users.
Additionally both methods used above place the file into a default directory. On UNIX systems the default directory is usually "/tmp" or "/var/tmp" and on Windows systems the default directory is usually "C:\\Windows\\Temp", which may be easily accessible to attackers, possibly enabling them to read and modify the contents of the temp file.
ExploitPedia is constantly evolving. Sign up to receive a notification when we release additional functionality.
If you'd like to report a bug or have any suggestions for improvements then please do get in touch with us using this form. We will get back to you as soon as we can.