RHSA-2021:1853 — Security Advisory
Red Hat Security Advisory: unbound security, bug fix, and enhancement update
Severity
ModerateRed Hat Product Security
Products
Official CSAF product identity
Published · May 18, 2021
Updated · June 27, 2026
Topic
An update for unbound is now available for Red Hat Enterprise Linux 8.
Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
The unbound packages provide a validating, recursive, and caching DNS or DNSSEC resolver.
Security Fix(es):
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unbound: integer overflow in the regional allocator via regional_alloc (CVE-2019-25032)
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unbound: integer overflow in sldns_str2wire_dname_buf_origin can lead to an out-of-bounds write (CVE-2019-25034)
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unbound: out-of-bounds write in sldns_bget_token_par (CVE-2019-25035)
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unbound: assertion failure and denial of service in synth_cname (CVE-2019-25036)
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unbound: assertion failure and denial of service in dname_pkt_copy via an invalid packet (CVE-2019-25037)
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unbound: integer overflow in a size calculation in dnscrypt/dnscrypt.c (CVE-2019-25038)
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unbound: integer overflow in a size calculation in respip/respip.c (CVE-2019-25039)
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unbound: infinite loop via a compressed name in dname_pkt_copy (CVE-2019-25040)
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unbound: assertion failure via a compressed name in dname_pkt_copy (CVE-2019-25041)
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unbound: out-of-bounds write via a compressed name in rdata_copy (CVE-2019-25042)
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unbound: symbolic link traversal when writing PID file (CVE-2020-28935)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Additional Changes:
For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.4 Release Notes linked from the References section.