Bug 1607283 – CVE-2018-4182 cups: Sandbox bypass due to insecure error handling

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Bug 1607283 - (CVE-2018-4182) CVE-2018-4182 cups: Sandbox bypass due to insecure error handling

Summary:	CVE-2018-4182 cups: Sandbox bypass due to insecure error handling

Status:	CLOSED NOTABUG

Aliases:	CVE-2018-4182

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	high Severity high
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=important,public=20180509,repo...
Keywords:	Security

Depends On:	1607295 1607293
Blocks:	1607292
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Reported:	2018-07-23 04:08 EDT by Andrej Nemec
Modified:	2018-08-28 10:08 EDT (History)
CC List:	12 users (show)

See Also:
Fixed In Version:
Doc Type:	If docs needed, set a value
Doc Text:	A Sandbox bypass has been discovered in cups on macOS due to insecure error handling. An attacker that has obtained sandboxed root access can use this flow to escape the sandbox.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2018-07-25 05:18:58 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
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oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
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Description Andrej Nemec 2018-07-23 04:08:50 EDT

It is possible to cause cups-exec to execute backends without a sandbox profile by causing cupsdCreateProfile() to fail.  An attacker that has obtained sandboxed root access can accomplish this by setting the CUPS temporary directory to immutable using chflags, which will prevent the profile from being written to disk.

References:

https://blog.gdssecurity.com/labs/2018/7/11/cups-local-privilege-escalation-and-sandbox-escapes.html

Upstream patch:

https://github.com/apple/cups/commit/d47f6aec436e0e9df6554436e391471097686ecc

Comment 1 Andrej Nemec 2018-07-23 04:31:41 EDT

Created cups tracking bugs for this issue:

Affects: fedora-all [bug 1607293]

Comment 3 Riccardo Schirone 2018-07-25 05:16:40 EDT

Fedora and RHEL are not affected by this flaw since Sandbox feature is not enabled on Linux.

Comment 4 Riccardo Schirone 2018-08-28 09:00:24 EDT

Statement:

This issue did not affect the versions of cups as shipped with Red Hat Enterprise Linux as cups on Linux does not support the Sandbox feature.

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