CVE-2019-11840

Description

An issue was discovered in the supplementary Go cryptography library, golang.org/x/crypto, before v0.0.0-20190320223903-b7391e95e576. A flaw was found in the amd64 implementation of the golang.org/x/crypto/salsa20 and golang.org/x/crypto/salsa20/salsa packages. If more than 256 GiB of keystream is generated, or if the counter otherwise grows greater than 32 bits, the amd64 implementation will first generate incorrect output, and then cycle back to previously generated keystream. Repeated keystream bytes can lead to loss of confidentiality in encryption applications, or to predictability in CSPRNG applications.

How to fix CVE-2019-11840

To remediate CVE-2019-11840, upgrade the affected package to a fixed version below.

—upgrade to 0.0~hg190-1+deb8u1 or later
—upgrade to 1:0.0~git20181203.505ab14-1+deb10u1 or later
—upgrade to 1:0.0~git20170407.0.55a552f+REALLY.0.0~git20161012.0.5f31782-1+deb8u1 or later
—upgrade to 1:0.0~git20200221.2aa609c-1 or later
—upgrade to 0.0.7-1+deb8u1 or later
—upgrade to 1.35-1+deb8u1 or later
—upgrade to 2.21-2+deb9u1 or later
—upgrade to 0.0.0-20190320223903-b7391e95e576 or later
—upgrade to 0.0.0-20190320223903-b7391e95e576 or later

Is CVE-2019-11840 being exploited?

Low — EPSS is 2.1%, meaning exploitation activity has not been observed at scale.

Affected packages (9)

from 0, < 0.0~hg190-1+deb8u1
from 0, < 1:0.0~git20181203.505ab14-1+deb10u1
from 0, < 1:0.0~git20170407.0.55a552f+REALLY.0.0~git20161012.0.5f31782-1+deb8u1
from 0, < 1:0.0~git20200221.2aa609c-1
from 0, < 0.0.7-1+deb8u1
from 0, < 1.35-1+deb8u1
from 0, < 2.21-2+deb9u1
from 0, < 0.0.0-20190320223903-b7391e95e576
from 0, < 0.0.0-20190320223903-b7391e95e576

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 3.1	MEDIUM5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N