Skip to content
Fencer Vulns
medium 6.5

CVE-2023-23915 json

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality to behave incor…

published 2023-02-23 3 y ago modified 2026-10-24 15 d ago also EUVD-2023-27997 , JLSEC-2026-403

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality to behave incorrectly when multiple URLs are requested in parallel. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This HSTS mechanism would however surprisingly fail when multiple transfers are done in parallel as the HSTS cache file gets overwritten by the most recentlycompleted transfer. A later HTTP-only transfer to the earlier host name would then *not* get upgraded properly to HSTS.

Patch / fix

  • julia CURL_jll 8.5.0+0
  • julia LibCURL_jll 7.88.1+0
  • 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
  • curl Debian 14, Debian 13, Debian 12 7.88.1-1

debian advisories DEBIAN-CVE-2023-23915

  • curl Ubuntu 22.04 LTS 7.81.0-1ubuntu1.8

ubuntu advisories UBUNTU-CVE-2023-23915

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

  • jbcs-httpd24-curl jboss core services 1 8.0.1-1.el7jbcs
  • jbcs-httpd24-curl jboss core services 1 8.0.1-1.el8jbcs
  • jbcs-httpd24-httpd jboss core services 1 2.4.51-39.el7jbcs
  • jbcs-httpd24-httpd jboss core services 1 2.4.51-39.el8jbcs
  • jbcs-httpd24-libcurl jboss core services 1 8.0.1-1.el7jbcs
  • jbcs-httpd24-libcurl jboss core services 1 8.0.1-1.el8jbcs
  • jbcs-httpd24-mod_ssl jboss core services 1 1:2.4.51-39.el7jbcs
  • jbcs-httpd24-mod_ssl jboss core services 1 1:2.4.51-39.el8jbcs

red hat advisories RHSA-2023:3354

  • curl SLE Module for Basesystem 15 SP4, SLE Micro 5.3, openSUSE Leap Micro 5.3 +1 more 7.79.1-150400.5.15.1

suse advisories SUSE-SU-2023:0429-1

  • curl openSUSE Tumbleweed 7.88.1-1.1

opensuse advisories openSUSE-SU-2024:12735-1

  • curl Alpine 3.14 7.79.1-r5
  • curl Alpine 3.15 7.80.0-r6
  • curl Alpine 3.16 7.83.1-r6
  • curl Alpine 3.17 7.87.0-r2
  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 7.88.0-r0

alpine advisories ALPINE-CVE-2023-23915

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

  • cmake CBL-Mariner 2.0 3.21.4-5
  • curl CBL-Mariner 2.0 7.88.1-1
  • mysql CBL-Mariner 2.0 8.0.33-1
  • rust CBL-Mariner 2.0 1.72.0-2
  • cmake Azure Linux 3.0 3.28.2-1
  • tensorflow Azure Linux 3.0 2.16.1-1

azure linux advisories AZL-13649AZL-13652AZL-13655AZL-13660AZL-34601AZL-38093

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-2023-23915 updated cvss 4.2

curl: HSTS amnesia with --parallel

  • Red Hat .NET Core 3.1 on Red Hat Enterprise Linux rh-dotnet31-curl, rh-dotnet31-libcurl
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat JBCS httpd 2.4.51.sp2
    fixed: vendor fix RHSA-2023:3355
  • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-curl 8.0.1-1.el7jbcs, jbcs-httpd24-libcurl 8.0.1-1.el7jbcs Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-curl 8.0.1-1.el8jbcs, jbcs-httpd24-libcurl 8.0.1-1.el8jbcs
    fixed: vendor fix RHSA-2023:3354
  • Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat Enterprise Linux 8 curl, libcurl, libcurl-minimal Red Hat Enterprise Linux 9 curl, libcurl, curl-minimal, libcurl-minimal Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-httpd 2.4.51-39.el7jbcs, jbcs-httpd24-mod_md 2.4.0-20.el7jbcs, jbcs-httpd24-mod_ssl 2.4.51-39.el7jbcs, jbcs-httpd24-openssl 1.1.1k-14.el7jbcs, jbcs-httpd24-apr-util 1.6.1-101.el7jbcs, jbcs-httpd24-mod_ldap 2.4.51-39.el7jbcs, +21 more Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-httpd 2.4.51-39.el8jbcs, jbcs-httpd24-mod_md 2.4.0-20.el8jbcs, jbcs-httpd24-mod_ssl 2.4.51-39.el8jbcs, jbcs-httpd24-openssl 1.1.1k-14.el8jbcs, jbcs-httpd24-apr-util 1.6.1-101.el8jbcs, jbcs-httpd24-mod_ldap 2.4.51-39.el8jbcs, +21 more
    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 ICSA-23-348-10 updated cvss 6.5

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 SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.88% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
julia CURL_jll
<8.5.0+0
8.5.0+0
julia LibCURL_jll
>=7.81.0+0, <7.88.1+0
7.88.1+0

Affected products

  • n/a https://github.com/curl/curl
  • 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
  • CWE-319 Cleartext Transmission of Sensitive Information

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.