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Security Advisories: GSA_kwCzR0hTQS1odnA1LTV4NGYtMzNmcc4AA7PK

JADX file override vulnerability

Summary

when jadx parses a resource file, there is an escape problem with the style file, which can overwrite other files in the directory when saving the decompile result.

Although I don't think this vulnerability realizes path traversal in the true sense of the word , I reported it anyway

Details

I see that getResAlias does something with the filename.

private String getResAlias(int resRef, String origKeyName, @Nullable FieldNode constField) {

but type style will return the original filename directly.

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so our goal is to take a malicious file that was originally of type raw, modify its type to style, trick jadx into

step1

create an android project using androidstudio and create a raw folder with the name attack_file_sayhiiiiiiiiiiiii, it doesn't matter what the content is!

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generate an initial APK

step2

extract this initial APK using ZIP software to get resources.arsc

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drop resources.arsc into 010editor

step3

search for the previous filename attack_file_sayhiiiiiiiiiiiii , two will appear here, we choose the second one

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let's change the name of the file here. I'll change it to ../../_file_sayhiiiiiiiiiiiii

note that you can only overwrite files in the folder where the decompile was saved.

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step4

change the type of this file to style

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modified to 0E

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step5

After saving, re-compress the whole folder into a zip, then change the extension to APK.

open it with JADX and you can see that it has been changed to a style type.

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click save all

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you can see the file escaping.

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so we can also construct a

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so the classes.dex file is also replaced here

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PoC

the details above have been written

Impact

latest version

Permalink: https://github.com/advisories/GHSA-hvp5-5x4f-33fq
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS1odnA1LTV4NGYtMzNmcc4AA7PK
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Low
Classification: General
Published: about 1 month ago
Updated: about 1 month ago


CVSS Score: 3.3
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Identifiers: GHSA-hvp5-5x4f-33fq
References: Repository: https://github.com/skylot/jadx
Blast Radius: 4.1

Affected Packages

maven:io.github.skylot:jadx-core
Dependent packages: 0
Dependent repositories: 18
Downloads:
Affected Version Ranges: < 1.5.0
Fixed in: 1.5.0
All affected versions: 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.4.4, 1.4.5, 1.4.6, 1.4.7
All unaffected versions: 1.5.0