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Fencer Vulns
high 7.4

CVE-2023-0361 json

A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS.

published 2023-02-15 3 y ago modified 2026-10-14 25 d ago also EUVD-2023-12422

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS. This side-channel can be sufficient to recover the key encrypted in the RSA ciphertext across a network in a Bleichenbacher style attack. To achieve a successful decryption the attacker would need to send a large amount of specially crafted messages to the vulnerable server. By recovering the secret from the ClientKeyExchange message, the attacker would be able to decrypt the application data exchanged over that connection.

Patch / fix

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • gnutls28 Debian 14, Debian 13, Debian 12 3.7.8-5

debian advisories DEBIAN-CVE-2023-0361

  • gnutls28 Ubuntu 20.04 LTS 3.6.13-2ubuntu1.8
  • gnutls28 Ubuntu 22.04 LTS 3.7.3-4ubuntu1.2

ubuntu advisories UBUNTU-CVE-2023-0361

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

  • gnutls RHEL 8 3.6.16-6.el8_7
  • gnutls-c++ RHEL 8 3.6.16-6.el8_7
  • gnutls-dane RHEL 8 3.6.16-6.el8_7
  • gnutls-utils RHEL 8 3.6.16-6.el8_7
  • gnutls RHEL 9 3.7.6-18.el9_1
  • gnutls-c++ RHEL 9 3.7.6-18.el9_1
  • gnutls-dane RHEL 9 3.7.6-18.el9_1
  • gnutls-utils RHEL 9 3.7.6-18.el9_1

red hat advisories RHSA-2023:3361RHSA-2023:1569RHSA-2023:1200RHSA-2023:1141

  • gnutls SLE Micro 5.3 3.7.3-150400.1.3.1
  • gnutls SLE Real Time 15 SP3, SLE Micro 5.2, SLE Micro 5.1 3.6.7-150200.14.25.2
  • gnutls SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 3.7.3-150400.4.27.1
  • gnutls SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLE High Performance Computing 15 SP1-LTSS 3.6.7-150000.6.50.1

suse advisories SUSE-SU-2024:1179-1SUSE-SU-2023:4952-1SUSE-SU-2023:0610-1SUSE-SU-2023:0475-1

  • gnutls openSUSE Tumbleweed 3.7.9-1.2

opensuse advisories openSUSE-SU-2024:12699-1

  • gnutls AlmaLinux 8 3.6.16-6.el8_7
  • gnutls-c++ AlmaLinux 8 3.6.16-6.el8_7
  • gnutls-dane AlmaLinux 8 3.6.16-6.el8_7
  • gnutls-utils AlmaLinux 8 3.6.16-6.el8_7
  • gnutls AlmaLinux 9 3.7.6-18.el9_1
  • gnutls-c++ AlmaLinux 9 3.7.6-18.el9_1
  • gnutls-dane AlmaLinux 9 3.7.6-18.el9_1
  • gnutls-utils AlmaLinux 9 3.7.6-18.el9_1

almalinux advisories ALSA-2023:1569ALSA-2023:1141

  • gnutls Rocky Linux 8 3.6.16-6.el8_7
  • gnutls Rocky Linux 9 3.7.6-18.el9_1

rocky linux advisories RLSA-2023:1569RLSA-2023:1141

  • gnutls Alpine 3.15, Alpine 3.14 3.7.1-r2
  • gnutls Alpine 3.16 3.7.7-r1
  • gnutls Alpine 3.17 3.7.8-r3
  • gnutls Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 3.8.0-r0

alpine advisories ALPINE-CVE-2023-0361

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

  • gnutls CBL-Mariner 2.0 3.7.7-2

azure linux advisories AZL-13568

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2023-0361 updated cvss 7.4

gnutls: timing side-channel in the TLS RSA key exchange code

  • Red Hat Enterprise Linux 6 gnutls, gnutls-guile, gnutls-utils Red Hat Enterprise Linux 7 gnutls, gnutls-c++, gnutls-dane, gnutls-utils
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) gnutls-c++ 3.6.16-6.el8_7, gnutls-dane 3.6.16-6.el8_7, gnutls-utils 3.6.16-6.el8_7
    fixed: vendor fix RHSA-2023:1569
  • Red Hat Enterprise Linux AppStream (v. 9) gnutls-c++ 3.7.6-18.el9_1, gnutls-dane 3.7.6-18.el9_1, gnutls-utils 3.7.6-18.el9_1
    fixed: vendor fix RHSA-2023:1141
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) gnutls-c++ 3.6.16-5.el8_6.1, gnutls-dane 3.6.16-5.el8_6.1, gnutls-utils 3.6.16-5.el8_6.1
    fixed: vendor fix RHSA-2023:3361
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) gnutls-c++ 3.7.6-18.el9_0, gnutls-dane 3.7.6-18.el9_0, gnutls-utils 3.7.6-18.el9_0
    fixed: vendor fix RHSA-2023:1200
  • Red Hat Enterprise Linux BaseOS (v. 8) gnutls 3.6.16-6.el8_7
    fixed: vendor fix RHSA-2023:1569
  • Red Hat Enterprise Linux BaseOS (v. 9) gnutls 3.7.6-18.el9_1
    fixed: vendor fix RHSA-2023:1141
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) gnutls 3.6.16-5.el8_6.1
    fixed: vendor fix RHSA-2023:3361
show 1 more
  • Red Hat Enterprise Linux BaseOS EUS (v.9.0) gnutls 3.7.6-18.el9_0
    fixed: vendor fix RHSA-2023:1200

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 ICSA-23-348-10 updated cvss 7.4

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-24-046-11 updated cvss 7.4

Siemens SCALANCE XCM-/XRM-300

  • Siemens SCALANCE XCH328 (6GK5328-4TS01-2EC2) <V2.4 Siemens SCALANCE XCM324 (6GK5324-8TS01-2AC2) <V2.4 Siemens SCALANCE XCM328 (6GK5328-4TS01-2AC2) <V2.4 Siemens SCALANCE XCM332 (6GK5332-0GA01-2AC2) <V2.4 Siemens SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3) <V2.4 Siemens SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) <V2.4
    +5 more products
    Siemens SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3) <V2.4
    affected: fixed in V2.4 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
19 mo ago

Exploit prediction

1.45% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.com https://gitlab.com/gnutls/gnutls/-/issues/1050 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • n/a gnutls
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness

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.