Is CVE-2023-27535 in the CISA KEV catalog?

No. CVE-2023-27535 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2023-27535?

CVE-2023-27535 has a CVSS v3 base score of 5.9 (MEDIUM).

What is the EPSS score for CVE-2023-27535?

CVE-2023-27535 has an EPSS score of 1.61% (73th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2023-27535?

Upgrade curl on debian 11 to 7.74.0-1.3+deb11u8 or later. Fixes are available for 27 affected products.

CVE & CISA-KEV Catalog

CVE-2023-27535

MEDIUMEPSS 73th pctl

5.9

CVSS v3

NVD

Description

An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.

CWE-305 CWE-287Improper Authentication

How to fix

Remediation Available

curlDebian

Fixed in:7.74.0-1.3+deb11u8CVE-2023-27535

Fixed in:7.88.1-7CVE-2023-27535

curlRed Hat / RHEL

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curlRocky

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-debuginfoRocky

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-debuginfoRed Hat / RHEL

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-debugsourceRocky

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-debugsourceRed Hat / RHEL

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-minimalRed Hat / RHEL

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-minimalRocky

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-minimal-debuginfoRed Hat / RHEL

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curl-minimal-debuginfoRocky

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurlRocky

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurlRed Hat / RHEL

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-debuginfoRocky

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-debuginfoRed Hat / RHEL

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-develRocky

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-develRed Hat / RHEL

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-minimalRed Hat / RHEL

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-minimalRocky

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-minimal-debuginfoRed Hat / RHEL

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

libcurl-minimal-debuginfoRocky

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.61.1-30.el8_8.2RHSA-2023:3106

Fixed in:0:7.61.1-22.el8_6.12RHSA-2024:0428

Fixed in:0:7.76.1-23.el9_2.1RHSA-2023:2650

curlUbuntu

Fixed in:7.35.0-1ubuntu2.20+esm15USN-5964-2

Fixed in:7.47.0-1ubuntu2.19+esm8USN-5964-2

Fixed in:7.58.0-2ubuntu3.24USN-5964-1

Fixed in:7.68.0-1ubuntu2.18USN-5964-1

Fixed in:7.81.0-1ubuntu1.10USN-5964-1

Fixed in:7.85.0-1ubuntu0.5USN-5964-1

libcurl3Ubuntu

Fixed in:7.35.0-1ubuntu2.20+esm15USN-5964-2

Fixed in:7.47.0-1ubuntu2.19+esm8USN-5964-2

libcurl3-gnutlsUbuntu

Fixed in:7.35.0-1ubuntu2.20+esm15USN-5964-2

Fixed in:7.47.0-1ubuntu2.19+esm8USN-5964-2

Fixed in:7.58.0-2ubuntu3.24USN-5964-1

Fixed in:7.68.0-1ubuntu2.18USN-5964-1

Fixed in:7.81.0-1ubuntu1.10USN-5964-1

Fixed in:7.85.0-1ubuntu0.5USN-5964-1

libcurl3-nssUbuntu

Fixed in:7.35.0-1ubuntu2.20+esm15USN-5964-2

Fixed in:7.47.0-1ubuntu2.19+esm8USN-5964-2

Fixed in:7.58.0-2ubuntu3.24USN-5964-1

Fixed in:7.68.0-1ubuntu2.18USN-5964-1

Fixed in:7.81.0-1ubuntu1.10USN-5964-1

Fixed in:7.85.0-1ubuntu0.5USN-5964-1

libcurl4Ubuntu

Fixed in:7.58.0-2ubuntu3.24USN-5964-1

Fixed in:7.68.0-1ubuntu2.18USN-5964-1

Fixed in:7.81.0-1ubuntu1.10USN-5964-1

Fixed in:7.85.0-1ubuntu0.5USN-5964-1

UniversalForwarderWindows application

Affected:8.2.0 8.2.12Fixed in:8.2.12Splunk, Inc.

Affected:9.0.0 9.0.6Fixed in:9.0.6Splunk, Inc.

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploit Intelligence

1.61%probability of exploitation in 30 days

73rdpercentile

Elevated risk: more likely to be exploited than 73% of all known CVEs.

References

Exploit1

hackerone.com

Third-Party Advisory4

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-06-09.