Bug 2033690 (CVE-2021-44538) - CVE-2021-44538 libolm: buffer overflow in olm_session_describe() via a crafted sequence of messages
Summary: CVE-2021-44538 libolm: buffer overflow in olm_session_describe() via a crafte...
Keywords:
Status: CLOSED UPSTREAM
Alias: CVE-2021-44538
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2033691 2033692
Blocks:
TreeView+ depends on / blocked
 
Reported: 2021-12-17 16:16 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-12-17 16:56 UTC (History)
1 user (show)

Fixed In Version:
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Last Closed: 2021-12-17 16:56:29 UTC


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Description Guilherme de Almeida Suckevicz 2021-12-17 16:16:04 UTC
The olm_session_describe function in Matrix libolm before 3.2.7 is vulnerable to a buffer overflow. The Olm session object represents a cryptographic channel between two parties. Therefore, its state is partially controllable by the remote party of the channel. Attackers can construct a crafted sequence of messages to manipulate the state of the receiver's session in such a way that, for some buffer sizes, a buffer overflow happens on a call to olm_session_describe. Furthermore, safe buffer sizes were undocumented. The overflow content is partially controllable by the attacker and limited to ASCII spaces and digits. The known affected products are Element Web And SchildiChat Web.

Reference:
https://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrix-js-sdk

Comment 1 Guilherme de Almeida Suckevicz 2021-12-17 16:16:20 UTC
Created libolm tracking bugs for this issue:

Affects: epel-8 [bug 2033692]
Affects: fedora-all [bug 2033691]

Comment 2 Vitaly Zaitsev 2021-12-17 16:29:01 UTC
Too slow. Already fixed and pushed to stable.

Comment 3 Product Security DevOps Team 2021-12-17 16:56:28 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.


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