[Swan-dev] [Swan-announce] Security vulnerability in NSS crypto library affecting libreswan

The Libreswan Team team at libreswan.org
Tue Dec 7 20:11:58 EET 2021

Last week, Mozilla released a security advisory regarding a NSS
crypto library memory corruption bug:


Libreswan uses the NSS library and is vulnerable to this memory
corruption bug. While it is not trivial to exploit, the Libreswan Team
cannot rule out that this exploit can lead to an attacker gaining Remote
Code Execution on servers running libreswan. To trigger this exploit,
no authentication credentials are required.

The vulnerability uses a malicious X.509 certificate signature, but
even connections not using certificates and using authby=secret (PSK),
are still vulnerable because connections might still attempt to
process certificate payloads before switching to a better connection,
or to obtain a better ID of the remote peer.

There is no workaround for libreswan itself. Please upgrade to NSS
version 3.73 or look at the security updates for your Operating System
that address CVE-2021-43527.
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