Bug 2045572

Summary:	CVE-2022-0367 libmodbus: Heap-based Buffer Overflow in modbus_reply [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Pedro Sampaio <psampaio>
Component:	libmodbus	Assignee:	Eric Sandeen <esandeen>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	35	CC:	esandeen, john, stephane.raimbault
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-02-04 18:25:11 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:
Bug Blocks:	2045571

Description Pedro Sampaio 2022-01-25 17:32:47 UTC

This is an automatically created tracking bug!  It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.

For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.

For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs

When submitting as an update, use the fedpkg template provided in the next
comment(s).  This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.

Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.

NOTE: this issue affects multiple supported versions of Fedora. While only
one tracking bug has been filed, please correct all affected versions at
the same time.  If you need to fix the versions independent of each other,
you may clone this bug as appropriate.

Comment 1 Pedro Sampaio 2022-01-25 17:32:49 UTC

Use the following template to for the 'fedpkg update' request to submit an
update for this issue as it contains the top-level parent bug(s) as well as
this tracking bug.  This will ensure that all associated bugs get updated
when new packages are pushed to stable.

=====

# bugfix, security, enhancement, newpackage (required)
type=security

# low, medium, high, urgent (required)
severity=medium

# testing, stable
request=testing

# Bug numbers: 1234,9876
bugs=2045571,2045572

# Description of your update
notes=Security fix for [PUT CVEs HERE]

# Enable request automation based on the stable/unstable karma thresholds
autokarma=True
stable_karma=3
unstable_karma=-3

# Automatically close bugs when this marked as stable
close_bugs=True

# Suggest that users restart after update
suggest_reboot=False

======

Additionally, you may opt to use the bodhi web interface to submit updates:

https://bodhi.fedoraproject.org/updates/new

Comment 2 Eric Sandeen 2022-02-04 18:25:11 UTC

Only rawhide is affected; all released versions are prior to the introduction of this bug.

The commit which introduced the cut and paste error was:

commit 933ed4d3e9f226a21274ff33ebc735d50d5f0be9
Author: Stéphane Raimbault <stephane.raimbault>
Date:   Tue May 10 13:34:22 2016 +0200

    Change API modbus_mapping_(offsets_new) to (new_start_address)
    
    Related to 52ab1bbea760ed8eaca184f7d875a2f52a116d0f.
    The arguments have been changed (see documentation).
    
    https://groups.google.com/d/msg/libmodbus/aXO8nBzW4Ew/uVGTDmvvBAAJ

which did: 

@@ -1041,15 +1050,15 @@ int modbus_reply(modbus_t *ctx, const uint8_t *req,
             rsp_length = response_exception(
                 ctx, &sft,
                 MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE, rsp);
-        } else if (address < mb_mapping->offset_registers ||
-                   (addr + nb) > mb_mapping->nb_registers ||
-                   address_write < mb_mapping->offset_registers ||
-                   (addr_write + nb_write) > mb_mapping->nb_registers) {
+        } else if (mapping_address < 0 ||
+                   (mapping_address + nb) > mb_mapping->nb_registers ||
+                   mapping_address < 0 ||
+                   (mapping_address_write + nb_write) > mb_mapping->nb_registers) {
             if (ctx->debug) {
                 fprintf(stderr,

(note the 2nd "address_write" turned into "mapping_address" instead of "mapping_address" write) went into v3.1.3.

Older versions (i.e. anything older than rawhide) are not affected.