Bug 1954782 (CVE-2019-25036) - CVE-2019-25036 unbound: assertion failure and denial of service in synth_cname
Summary: CVE-2019-25036 unbound: assertion failure and denial of service in synth_cname
Alias: CVE-2019-25036
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1968662 1859933 1968663 1968664
Blocks: 1954811
TreeView+ depends on / blocked
Reported: 2021-04-28 18:46 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-06-14 07:14 UTC (History)
5 users (show)

Fixed In Version: unbound 1.9.6
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in unbound. A reachable assertion in the synth_cname function can be triggered by sending invalid packets to the server. If asserts are disabled during compilation, this issue might lead to an out-of-bounds write in dname_pkt_copy function. The highest threat from this vulnerability is to data confidentiality and integrity as well as service availability.
Clone Of:
Last Closed: 2021-05-18 20:39:03 UTC

Attachments (Terms of Use)

Description Guilherme de Almeida Suckevicz 2021-04-28 18:46:15 UTC
Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname.


Comment 1 Paul Wouters 2021-04-28 20:44:49 UTC
I no longer have permission to close this bug, or see what is blocking this. But it's an old resolved issue

Comment 3 Riccardo Schirone 2021-05-06 11:21:57 UTC

This issue could not be triggered by running unbound regularly, but only by injecting the packet directly to the vulnerable function through fuzzing. For this reason its Impact is Moderate.

Comment 5 errata-xmlrpc 2021-05-18 15:37:43 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1853 https://access.redhat.com/errata/RHSA-2021:1853

Comment 6 Product Security DevOps Team 2021-05-18 20:39:03 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


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