Bug 1903619 - dash: code is executed even if noexec ("-n") is specified
Summary: dash: code is executed even if noexec ("-n") is specified
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1903620 1903621
Blocks: 1903623
TreeView+ depends on / blocked
 
Reported: 2020-12-02 14:15 UTC by Michael Kaplan
Modified: 2021-02-16 18:48 UTC (History)
3 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2020-12-08 05:00:49 UTC
Embargoed:


Attachments (Terms of Use)

Description Michael Kaplan 2020-12-02 14:15:19 UTC
An issue was found in dash. Dash executes code even if "-n" / noexec is specified.

Comment 1 Michael Kaplan 2020-12-02 14:15:27 UTC
External References:

https://www.openwall.com/lists/oss-security/2020/11/11/3

Comment 2 Michael Kaplan 2020-12-02 14:15:45 UTC
Created dash tracking bugs for this issue:

Affects: epel-all [bug 1903621]
Affects: fedora-all [bug 1903620]

Comment 3 Doran Moppert 2020-12-08 05:00:31 UTC
A fix is committed upstream here:

https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=29d6f2148f10213de4e904d515e792d2cf8c968e

Consensus seems to be that while this is security relevant information, it's not worthy of a CVE.  The attack scenario would require that an attacker can provide arbitrary arguments to dash, but `-n` is always given and presumed to provide some security.  It's hard to imagine that this would be useful (since no script or tty command source can be used `-n`), or even presumed safe given all the other, interacting arguments dash can interpret.  If an attacker can perform command injection to `dash -n -c '<some-attacker-controlled-string>'`, that is a different vulnerability unrelated to `-n`.


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