CVE-2023-27537

mediumpriority · track · 25EPSS 0.019 · 80 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.90% (80th) EPSS
CVSS 5.9 · medium
Is it mine?
66 products
Check your exposure
Who says so?
7 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double-free or use-after-free.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

5.9
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 3.6
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · CISA US
v3.15.6mediumAV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:Lsecondary · FSTEC (BDU) RU
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-415USprimaryCWE-415USCWE-415USCWE-415US
04

affected products (66)

Products and version ranges known to be affected.

showing 20 of 66
05

advisories (8)

Vendor and ecosystem advisories describing this.

  • SSA-398330SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.52023-12-12csaf · siemens_psirtDE

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 are no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 (https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

  • SSA-943925SSA-943925: Multiple Vulnerabilities in SINEC NMS before V2.0 SP12024-02-13csaf · siemens_psirtDE

    SINEC NMS before V2.0 SP1 is affected by multiple vulnerabilities. Siemens has released an update for SINEC NMS and recommends to update to the latest version.

  • WID-SEC-W-2023-0690cURL: Mehrere SchwachstellenDeutsch2023-03-19csaf · cert_bundDE

    Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in cURL ausnutzen, um Informationen offenzulegen, Sicherheitsvorkehrungen zu umgehen oder unbekannte Auswirkungen zu verursachen.

  • WID-SEC-W-2023-1350Splunk Splunk Enterprise: Mehrere Schwachstellen in Komponenten von DrittanbieternDeutsch2023-06-01csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise in diversen Komponenten von Drittanbietern ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

  • WID-SEC-W-2023-2229Splunk Splunk Enterprise: Mehrere SchwachstellenDeutsch2023-08-30csaf · cert_bundDE

    Ein entfernter, authentifizierter Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise ausnutzen, um beliebigen Code auszuführen, einen 'Denial of Service'-Zustand zu verursachen, seine Privilegien zu erweitern und weitere, nicht spezifizierte Auswirkungen zu verursachen.

  • ICSA-23-348-10Siemens SIMATIC S7-15002023-12-12icsa · cisa_csaf_otUS

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

  • ICSA-24-046-15Siemens SINEC NMS2024-02-13icsa · cisa_csaf_otUS

    SINEC NMS before V2.0 SP1 is affected by multiple vulnerabilities. Siemens has released an update for SINEC NMS and recommends to update to the latest version.

  • CURL-CVE-2023-27537HSTS double free2023-03-20vendor · osvUS

    libcurl supports sharing HSTS data between separate "handles". This sharing was introduced without considerations for doing this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double free or use after free.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundsiemens_psirtcisa_csaf_otosvNVDCVE.orgMITRE
published 2023-03-30modified 2026-10-23
09

references (17)

External citations — patches, advisories, analysis.

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