CVE-2020-19467

Vulnerability

A use-after-free vulnerability exists in the DCTStream::transformDataUnit function of PDF2JSON version 0.70 (commit b671b64). The bug occurs when processing a specially crafted PDF file that triggers an improper memory deallocation sequence, leading to a read from a freed heap block during DCT stream decoding [1].

Exploitation

An attacker can exploit this issue by providing a malicious PDF file to the victim. No authentication or special network position is required; the victim only needs to open the file using PDF2JSON, for example via a command like pdf2json $PoC /dev/null. The crash reproduces reliably with the proof-of-concept file [1].

Impact

Successful exploitation causes a denial of service (application crash) due to an invalid memory read. The vector is local (user interaction), and the crash occurs during parsing, preventing normal file conversion [1]. No remote code execution or privilege escalation is indicated.

Mitigation

As of the latest referenced information (commit b671b64), no official fix has been released for this vulnerability. Users should avoid processing untrusted PDF files with PDF2JSON until a patched version is made available [1].