PT-2021-2209 · Dnsmasq+6 · Dnsmasq+6
Moshe Kol
+1
·
Published
2021-01-19
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Updated
2021-03-26
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CVE-2020-25682
CVSS v2.0
8.3
High
| Vector | AV:N/AC:M/Au:N/C:P/I:P/A:C |
Name of the Vulnerable Software and Affected Versions
dnsmasq versions prior to 2.83
Description
A buffer overflow vulnerability was discovered in the way dnsmasq extracts names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the
extract name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.Recommendations
As a temporary workaround, consider disabling the
extract name() function until a patch is available.
Update to version 2.83 or later to resolve the issue.Fix
Heap Based Buffer Overflow
Memory Corruption
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Related Identifiers
Affected Products
Alt Linux
Centos
Linuxmint
Red Hat
Suse
Ubuntu
Dnsmasq