Bug 1584412

Summary:	sharpziplib: zip slip - arbitrary file write vulnerability / arbitrary code execution using a specially crafted zip file
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	dmoppert, pokorra.mailinglists, security-response-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	sharpcompress 0.21.1	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-10 10:27:03 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1585948, 1585949
Bug Blocks:

Description Laura Pardo 2018-05-30 20:21:47 UTC

A vulnerability has been found in the way developers have implemented the archive extraction of files. An arbitrary file write vulnerability, that can be achieved using a specially crafted zip archive (affects other archives as well, bzip2, tar,xz, war, cpio, 7z), that holds path traversal filenames. So when the filename gets concatenated to the target extraction directory, the final path ends up outside of the target folder. Of course if an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily. This affects multiple libraries that lacks of a high level APIs that provide the archive extraction functionality.

Comment 1 Doran Moppert 2018-06-05 07:32:07 UTC

Public via:

https://snyk.io/vuln/SNYK-DOTNET-SHARPCOMPRESS-60246

Comment 2 Doran Moppert 2018-06-05 07:32:51 UTC

Created sharpziplib tracking bugs for this issue:

Affects: fedora-27 [bug 1585948]
Affects: fedora-28 [bug 1585949]

Comment 3 Timotheus Pokorra 2018-06-05 20:56:01 UTC

I had a look at https://github.com/snyk/zip-slip-vulnerability
It does not actually say that sharplibzip is vulnerable.

There does not seem to be an upstream bug for sharplibzip yet.

Comment 4 Doran Moppert 2018-06-06 01:10:29 UTC

(In reply to Timotheus Pokorra from comment #3)
> I had a look at https://github.com/snyk/zip-slip-vulnerability
> It does not actually say that sharplibzip is vulnerable.
> 
> There does not seem to be an upstream bug for sharplibzip yet.

hmm you're right, there seems to have been some confusion between this report and the one for sharpcompress.

The Snyk advisory lists sharpziplib as "lacks high-level API" which is only partially correct.  FastZip.cs and TarArchive.cs both include ExtractEntry methods which appear to be vulnerable.  The wiki examples also don't defend against these attacks, afaics.

This pull request against SharpCompress illustrates one strategy to fix:

https://github.com/adamhathcock/sharpcompress/pull/374

Comment 5 Timotheus Pokorra 2018-06-20 18:39:32 UTC

there is now an official bug upstream:
https://github.com/icsharpcode/SharpZipLib/issues/232

and a potential fix:
https://github.com/piksel/SharpZipLib/commit/79503293a6991d7074236b9442c151562b94c648

Comment 6 Product Security DevOps Team 2019-06-10 10:27:03 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.