Vigil@nce: flex, invalid code generation
February 2010 by Vigil@nce
An attacker can invite the victim to use flex with an invalid lex file, in order to generate incorrect C code.
Consequences: user access/rights, data reading, data creation/edition
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 16/02/2010
Unix - plateform
DESCRIPTION OF THE VULNERABILITY
The flex program reads a specification file defining rules composed of regular expressions and of code, and then generates a C program which executes the code when the related expression is found.
However, flex does not correctly handle comments nor yy_size_t sizes. The generated code is thus invalid.
An attacker can therefore invite the victim to use flex with an invalid lex file, in order to generate incorrect C code.
Identifiers: 1628314, 1849805, 1849809, 1849812, CVE-2010-0634,