Bug 1963977 (CVE-2021-28902) - CVE-2021-28902 libyang: NULL pointer dereference in read_yin_container()
Summary: CVE-2021-28902 libyang: NULL pointer dereference in read_yin_container()
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2021-28902
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: 1963978 1965252 1965253
Blocks: 1964021
TreeView+ depends on / blocked
 
Reported: 2021-05-24 14:10 UTC by Guilherme de Almeida Suckevicz
Modified: 2022-04-17 21:24 UTC (History)
2 users (show)

Fixed In Version: libyang 1.0.226
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in libyang. Missing checks in several read_yin_* functions lead to NULL pointer dereferences possibly allowing a remote attacker to crash an application that uses libyang with user-controlled YIN formats. The highest threat from this vulnerability is the service availability.
Clone Of:
Environment:
Last Closed: 2021-10-28 12:28:46 UTC
Embargoed:

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Description Guilherme de Almeida Suckevicz 2021-05-24 14:10:10 UTC 
In function read_yin_container() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a crash.

Reference:
https://github.com/CESNET/libyang/issues/1454
Comment 1 Guilherme de Almeida Suckevicz 2021-05-24 14:10:27 UTC 
Created libyang tracking bugs for this issue:

Affects: fedora-all [bug 1963978]
Comment 2 Riccardo Schirone 2021-05-27 09:19:39 UTC 
Upstream patch:
https://github.com/CESNET/libyang/commit/a3917d95d516e3de267d3cfa5d4d3715a90e8777
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