Add advisory text for CVE-2026-0951

Explain the security issue and set context for the vulnerability to help
downstreams get a better understanding of the issue.

Reviewed-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
This commit is contained in:
Carlos O'Donell 2026-01-16 08:14:49 -05:00
parent 75d8c149f8
commit ffe48207fd
1 changed files with 25 additions and 0 deletions

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getnetbyaddr and getnetbyaddr_r leak stack contents to DNS resovler
Calling getnetbyaddr or getnetbyaddr_r with a configured nsswitch.conf
that specifies the library's DNS backend for networks and queries for a
zero-valued network in the GNU C Library version 2.0 to version 2.42
can leak stack contents to the configured DNS resolver.
A defect in the _nss_dns_getnetbyaddr_r function which implements
getnetbyaddr and getnetbyaddr_r in the dns-based network database can
pass stack contents unmodified to the configured DNS resolver as part of
the network DNS query when the network queried is the default network
i.e. net == 0x0. This stack contents leaking in the query is considered
a loss of confidentiality for the host making the query. Typically it
is rare to call these APIs with a net value of zero, and if an attacker
can control the net value it can only leak adjacent stack, and so loss
of confidentiality is spatially limited. The leak might be used to
accelerate an ASLR bypass by knowing pointer values, but also requires
network adjacent access to snoop between the application and the
DNS server; making the attack complexity higher.
CVE-Id: CVE-2026-0915
Public-Date: 2026-01-15
Vulnerable-Commit: 5f0e6fc702296840d2daa39f83f6cb1e40073d58 (1.92-1)
Fix-Commit: e56ff82d5034ec66c6a78f517af6faa427f65b0b (2.43)
Reported-by: Igor Morgenstern, Aisle Research