Bug 2189103 (CVE-2021-46878)

Summary:	CVE-2021-46878 fluent-bit: type confusion causing use-after-free in flb_pack_msgpack_to_json_format
Product:	[Other] Security Response	Reporter:	Anten Skrabec <askrabec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	The package fluent-bit is vulnerable to a Use After Free due to erroneous parsing in the flb_pack_msgpack_to_json_format() function, which leads to type confusion.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-04-24 13:15:05 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:	2189104, 2189105
Bug Blocks:	2186018

Description Anten Skrabec 2023-04-24 08:35:25 UTC

An issue was discovered in Treasure Data Fluent Bit 1.7.1, erroneous parsing in flb_pack_msgpack_to_json_format leads to type confusion bug that interprets whatever is on the stack as msgpack maps and arrays, leading to use-after-free. This can be used by an attacker to craft a specially craft file and trick the victim opening it using the affect software, triggering use-after-free and execute arbitrary code on the target system.

Comment 1 Anten Skrabec 2023-04-24 08:35:40 UTC

Created fluent-bit tracking bugs for this issue:

Affects: epel-8 [bug 2189105]
Affects: fedora-all [bug 2189104]

Comment 2 Product Security DevOps Team 2023-04-24 13:15:03 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.