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Vulnerability details: VCID-cbah-e86c-w3fj
Vulnerability ID VCID-cbah-e86c-w3fj
Aliases CVE-2023-27535
Summary Improper Authentication 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.
Status Published
Exploitability 0.5
Weighted Severity 5.3
Risk 2.6
Affected and Fixed Packages Package Details
Weaknesses (4)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-287 Improper Authentication
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-305 Authentication Bypass by Primary Weakness
System Score Found at
cvssv3 5.9 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27535.json
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
epss 0.00065 https://api.first.org/data/v1/epss?cve=CVE-2023-27535
cvssv3.1 Medium https://curl.se/docs/CVE-2023-27535.html
cvssv3.1 5.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3.1 5.9 https://hackerone.com/reports/1892780
ssvc Track https://hackerone.com/reports/1892780
cvssv3.1 5.9 https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
ssvc Track https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
cvssv3.1 5.9 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
ssvc Track https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
cvssv3.1 5.9 https://security.gentoo.org/glsa/202310-12
ssvc Track https://security.gentoo.org/glsa/202310-12
cvssv3.1 5.9 https://security.netapp.com/advisory/ntap-20230420-0010/
ssvc Track https://security.netapp.com/advisory/ntap-20230420-0010/
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27535.json
https://api.first.org/data/v1/epss?cve=CVE-2023-27535
https://curl.se/docs/CVE-2023-27535.html
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-27535
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://hackerone.com/reports/1892780
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
2179073 https://bugzilla.redhat.com/show_bug.cgi?id=2179073
36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
CVE-2023-27535 https://nvd.nist.gov/vuln/detail/CVE-2023-27535
GLSA-202310-12 https://security.gentoo.org/glsa/202310-12
msg00025.html https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
ntap-20230420-0010 https://security.netapp.com/advisory/ntap-20230420-0010/
RHSA-2023:2650 https://access.redhat.com/errata/RHSA-2023:2650
RHSA-2023:3106 https://access.redhat.com/errata/RHSA-2023:3106
RHSA-2024:0428 https://access.redhat.com/errata/RHSA-2024:0428
USN-5964-1 https://usn.ubuntu.com/5964-1/
USN-5964-2 https://usn.ubuntu.com/5964-2/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-27535.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

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Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://hackerone.com/reports/1892780
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

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Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-03T18:24:11Z/ Found at https://hackerone.com/reports/1892780
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

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Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-03T18:24:11Z/ Found at https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

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unchanged

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Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-03T18:24:11Z/ Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://security.gentoo.org/glsa/202310-12
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

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none

required

unchanged

changed

high

low

none

high

low

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Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-03T18:24:11Z/ Found at https://security.gentoo.org/glsa/202310-12
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://security.netapp.com/advisory/ntap-20230420-0010/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

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none

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Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-03T18:24:11Z/ Found at https://security.netapp.com/advisory/ntap-20230420-0010/
Exploit Prediction Scoring System (EPSS)
Percentile 0.20386
EPSS Score 0.00065
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:51:05.113902+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/conan/libcurl/CVE-2023-27535.yml 38.0.0