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Fencer Vulns
medium 6.5

CVE-2023-23916 json

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algor…

published 2023-02-23 3 y ago modified 2026-10-23 16 d ago also EUVD-2023-27998 , JLSEC-2026-404

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits
0
none known

Summary

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with differentalgorithms. The number of acceptable "links" in this "decompression chain" wascapped, but the cap was implemented on a per-header basis allowing a maliciousserver to insert a virtually unlimited number of compression steps simply byusing many headers. The use of such a decompression chain could result in a "malloc bomb", making curl end up spending enormous amounts of allocated heap memory, or trying to and returning out of memory errors.

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-2023-23916

  • curl Ubuntu 18.04 LTS 7.58.0-2ubuntu3.23
  • curl Ubuntu 20.04 LTS 7.68.0-1ubuntu2.16
  • curl Ubuntu 22.04 LTS 7.81.0-1ubuntu1.8

ubuntu advisories UBUNTU-CVE-2023-23916

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-2023:3354RHSA-2023:4139RHSA-2023:3460RHSA-2023:1701RHSA-2023:1140RHSA-2023:1842

  • curl SLES for SAP 12 SP4, SLES 12 SP4-LTSS, SLES 12 SP4-ESPOS +2 more 7.60.0-4.56.1
  • curl SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLE High Performance Computing 15 SP1-LTSS +1 more 7.60.0-150000.51.1
  • curl SLE Real Time 15 SP3, SLE Micro 5.2, SLE Micro 5.1 7.66.0-150200.4.52.1
  • 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
  • curl SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 7.60.0-11.55.1

suse advisories SUSE-SU-2023:2228-1SUSE-SU-2023:2226-1SUSE-SU-2023:1711-1SUSE-SU-2023:0429-1SUSE-SU-2023:0425-1

  • curl openSUSE Tumbleweed 7.88.1-1.1

opensuse advisories openSUSE-SU-2024:12735-1

  • curl AlmaLinux 9 7.76.1-19.el9_1.2
  • libcurl AlmaLinux 9 7.76.1-19.el9_1.2
  • curl-minimal AlmaLinux 9 7.76.1-19.el9_1.2
  • libcurl-minimal AlmaLinux 9 7.76.1-19.el9_1.2
  • curl AlmaLinux 8 7.61.1-25.el8_7.3
  • libcurl AlmaLinux 8 7.61.1-25.el8_7.3
  • libcurl-minimal AlmaLinux 8 7.61.1-25.el8_7.3

almalinux advisories ALSA-2023:1701ALSA-2023:1140

  • curl Rocky Linux 8 7.61.1-25.el8_7.3

rocky linux advisories RLSA-2023:1140

  • 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-2023-23916

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 3.21.4-13
  • 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-13651AZL-13653AZL-13657AZL-13658AZL-34602AZL-37839

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-2023-23916 updated cvss 6.5

curl: HTTP multi-header compression denial of service

  • Red Hat .NET Core 3.1 on Red Hat Enterprise Linux rh-dotnet31-curl, rh-dotnet31-libcurl Red Hat Enterprise Linux 6 curl, libcurl
    affected: no fix planned “Out of support scope”
  • Red Hat JBCS httpd 2.4.51.sp2
    fixed: vendor fix RHSA-2023:3355
  • Red Hat Enterprise Linux AppStream (v. 9) libcurl-devel 7.76.1-19.el9_1.2, curl-debuginfo 7.76.1-19.el9_1.2, curl-debugsource 7.76.1-19.el9_1.2, libcurl-debuginfo 7.76.1-19.el9_1.2, curl-minimal-debuginfo 7.76.1-19.el9_1.2, libcurl-minimal-debuginfo 7.76.1-19.el9_1.2
    fixed: vendor fix RHSA-2023:1701
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) libcurl-devel 7.76.1-14.el9_0.6, curl-debuginfo 7.76.1-14.el9_0.6, curl-debugsource 7.76.1-14.el9_0.6, libcurl-debuginfo 7.76.1-14.el9_0.6, curl-minimal-debuginfo 7.76.1-14.el9_0.6, libcurl-minimal-debuginfo 7.76.1-14.el9_0.6
    fixed: vendor fix RHSA-2023:4139
  • Red Hat Enterprise Linux BaseOS (v. 8) curl 7.61.1-25.el8_7.3, libcurl 7.61.1-25.el8_7.3, libcurl-minimal 7.61.1-25.el8_7.3
    fixed: vendor fix RHSA-2023:1140
  • Red Hat Enterprise Linux BaseOS (v. 9) curl 7.76.1-19.el9_1.2, libcurl 7.76.1-19.el9_1.2, curl-minimal 7.76.1-19.el9_1.2, libcurl-minimal 7.76.1-19.el9_1.2
    fixed: vendor fix RHSA-2023:1701
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) curl 7.61.1-18.el8_4.3, libcurl 7.61.1-18.el8_4.3, libcurl-minimal 7.61.1-18.el8_4.3 Red Hat Enterprise Linux BaseOS E4S (v.8.4) curl 7.61.1-18.el8_4.3, libcurl 7.61.1-18.el8_4.3, libcurl-minimal 7.61.1-18.el8_4.3
    fixed: vendor fix RHSA-2023:3460
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) curl 7.61.1-22.el8_6.6, libcurl 7.61.1-22.el8_6.6, libcurl-minimal 7.61.1-22.el8_6.6
    fixed: vendor fix RHSA-2023:1842
show 4 more
  • Red Hat Enterprise Linux BaseOS EUS (v.9.0) curl 7.76.1-14.el9_0.6, libcurl 7.76.1-14.el9_0.6, curl-minimal 7.76.1-14.el9_0.6, libcurl-minimal 7.76.1-14.el9_0.6
    fixed: vendor fix RHSA-2023:4139
  • Red Hat Enterprise Linux BaseOS TUS (v.8.4) curl 7.61.1-18.el8_4.3, libcurl 7.61.1-18.el8_4.3, libcurl-minimal 7.61.1-18.el8_4.3
    fixed: vendor fix RHSA-2023:3460
  • 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 7 curl, libcurl 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 ICSA-23-129-02 updated cvss 7.5

Hitachi Energy MSM

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

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

Exploit prediction

1.74% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/1826048 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

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

Affected packages

ecosystem package affected fixed in
julia CURL_jll
<8.5.0+0
8.5.0+0
julia LibCURL_jll
<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-770 Allocation of Resources Without Limits or Throttling

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.