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Fencer Vulns
high 7.4

CVE-2019-1543 json

ChaCha20-Poly1305 with long nonces

published 2019-03-06 7 y ago modified 2026-11-02 6 d ago also EUVD-2019-10100

cvss
7.4
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.7%
EPSS 5.7% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if it is less than 12 bytes. However it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only the last 12 bytes are significant and any additional leading bytes are ignored. It is a requirement of using this cipher that nonce values are unique. Messages encrypted using a reused nonce value are susceptible to serious confidentiality and integrity attacks. If an application changes the default nonce length to be longer than 12 bytes and then makes a change to the leading bytes of the nonce expecting the new value to be a new unique nonce then such an application could inadvertently encrypt messages with a reused nonce. Additionally the ignored bytes in a long nonce are not covered by the integrity guarantee of this cipher. Any application that relies on the integrity of these ignored leading bytes of a long nonce may be further affected. Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe because no such use sets such a long nonce value. However user applications that use this cipher directly and set a non-default nonce length to be longer than 12 bytes may be vulnerable. OpenSSL versions 1.1.1 and 1.1.0 are affected by this issue. Due to the limited scope of affected deployments this has been assessed as low severity and therefore we are not creating new releases at this time. Fixed in OpenSSL 1.1.1c (Affected 1.1.1-1.1.1b). Fixed in OpenSSL 1.1.0k (Affected 1.1.0-1.1.0j).

Patch / fix

  • openssl Debian 14, Debian 13, Debian 12 1.1.1c-1

debian advisories DEBIAN-CVE-2019-1543

  • openssl Ubuntu 18.04 LTS 1.1.1-1ubuntu2.1~18.04.2

ubuntu advisories UBUNTU-CVE-2019-1543

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openssl RHEL 8 1:1.1.1c-2.el8
  • openssl-libs RHEL 8 1:1.1.1c-2.el8
  • openssl-perl RHEL 8 1:1.1.1c-2.el8

red hat advisories RHSA-2019:3700

  • openssl-1_1 SLES for SAP 12 SP4, SLES 12 SP4, SLED 12 SP4 +1 more 1.1.1-2.9.1
  • openssl-1_1 SLE Module for Basesystem 15 1.1.0i-4.21.1

suse advisories SUSE-SU-2019:0787-1SUSE-SU-2019:0678-1

  • openssl-1_1 openSUSE Tumbleweed 1.1.1l-1.2
  • virtualbox openSUSE Leap 15.1, openSUSE Leap 15.0 6.0.10-lp151.2.6.1
  • openssl-1_1 openSUSE Leap 15.0 1.1.0i-lp150.3.22.3

opensuse advisories openSUSE-SU-2024:11127-1openSUSE-SU-2019:1814-1openSUSE-SU-2019:1147-1

  • file Alpine 3.24, Alpine 3.23, Alpine 3.22 +12 more 5.36-r0
  • openssl Alpine 3.24, Alpine 3.23, Alpine 3.22 +13 more 1.1.1b-r1
  • openssl3 Alpine 3.16, Alpine 3.15 1.1.1b-r1
  • openssl1.1-compat Alpine 3.18, Alpine 3.17 1.1.1b-r1

alpine advisories ALPINE-CVE-2019-1543

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openssl Arch Linux 1.1.1.c-1
  • lib32-openssl Arch Linux 1:1.1.1.c-1

arch linux advisories AVG-919AVG-920

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-1543 updated cvss 2.9

openssl: ChaCha20-Poly1305 with long nonces

  • Red Hat Enterprise Linux BaseOS (v. 8) openssl 1.1.1c-2.el8, openssl-libs 1.1.1c-2.el8, openssl-perl 1.1.1c-2.el8
    fixed: vendor fix RHSA-2019:3700
  • Red Hat Enterprise Linux 5 openssl, openssl097a Red Hat Enterprise Linux 6 openssl, openssl098e, openssl-perl Red Hat Enterprise Linux 7 OVMF, openssl, openssl098e, openssl-libs, openssl-perl Red Hat Enterprise Linux 8 mingw-openssl, mingw32-openssl, mingw64-openssl, compat-openssl10 Red Hat JBoss Core Services jbcs-httpd24-openssl Red Hat JBoss Enterprise Application Platform 5 openssl
    +4 more products
    Red Hat JBoss Enterprise Application Platform 6 openssl Red Hat JBoss Enterprise Web Server 2 openssl Red Hat JBoss Web Server 3 openssl Red Hat JBoss Web Server 5 openssl
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 d ago

Exploit prediction

5.70% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.4 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N

Affected products

  • OpenSSL OpenSSL

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-330 Use of Insufficiently Random Values
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.