JasPer Assertion Failure Vulnerability in JPEG2000 Encoder

An assertion failure vulnerability has been identified in JasPer versions through 4.2.5, specifically within the JPEG2000 Encoder component. The issue arises in the 'jpc_floorlog2' function of 'src/libjasper/jpc/jpc_enc.c', where the function fails to properly validate input parameters. This flaw allows for the assertion 'x > 0' to be bypassed, leading to a program crash. The vulnerability requires local exploitation and has been publicly disclosed, with an available proof-of-concept exploit.

Impact

Exploitation of this vulnerability causes a program crash due to a failed assertion, which interrupts the normal execution flow and terminates the process.

Reproduction

The vulnerability can be reproduced by using the JasPer command-line tool to encode a JPEG2000 image while specifying an invalid 'cblkwidth' parameter. This can be done by leaving the parameter value empty, which will be interpreted as zero. When the 'jpc_floorlog2' function processes this value, the assertion will fail, causing the program to abort.

Remediation

Users are advised to update to JasPer version 4.2.8 or later, where this vulnerability has been fixed.