Bug 2029513 (CVE-2021-4069)

Summary:	CVE-2021-4069 vim: use-after-free in ex_open() in src/ex_docmd.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	bdettelb, caswilli, fjansen, gchamoul, gparvin, jburrell, jwong, karsten, kaycoth, pahickey, stcannon, vkumar, vmugicag, zdohnal
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	vim 8.2.3741	Doc Type:	If docs needed, set a value
Doc Text:	A heap use-after-free flaw was found in Vim's ex_open() function in src/ex_docmd.c file. This flaw allows an attacker to trick the victim into opening a specially crafted file that triggers a use-after-free error, allowing the attacker to compromise the system and execute arbitrary code.	Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	2029514, 2029776, 2029783
Bug Blocks:	2029515

Description Guilherme de Almeida Suckevicz 2021-12-06 16:51:02 UTC

Vim is vulnerable to use-after-free.

Reference:
https://huntr.dev/bounties/0efd6d23-2259-4081-9ff1-3ade26907d74

Upstream patch:
https://github.com/vim/vim/commit/e031fe90cf2e375ce861ff5e5e281e4ad229ebb9

Comment 1 Guilherme de Almeida Suckevicz 2021-12-06 16:51:17 UTC

Created vim tracking bugs for this issue:

Affects: fedora-all [bug 2029514]

Comment 2 lnacshon 2021-12-07 09:54:58 UTC

published PCO

Create a file with content 
)/\v/
o/\%')

execute vim -u NONE -X -Z -e -s -S file -c :qa!