{"id":"UBUNTU-CVE-2023-27535","details":"An authentication bypass vulnerability exists in libcurl \u003c8.0.0 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.","modified":"2026-04-22T16:39:29.402619Z","published":"2023-03-20T00:00:00Z","related":["USN-5964-1","USN-5964-2"],"upstream":["CVE-2023-27535"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-27535"},{"type":"REPORT","url":"https://curl.se/docs/CVE-2023-27535.html"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5964-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5964-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-27535"}],"affected":[{"package":{"name":"curl","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/curl@7.35.0-1ubuntu2.20+esm15?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.35.0-1ubuntu2.20+esm15"}]}],"versions":["7.32.0-1ubuntu1","7.33.0-1ubuntu1","7.34.0-1ubuntu1","7.35.0-1ubuntu1","7.35.0-1ubuntu2","7.35.0-1ubuntu2.1","7.35.0-1ubuntu2.2","7.35.0-1ubuntu2.3","7.35.0-1ubuntu2.5","7.35.0-1ubuntu2.6","7.35.0-1ubuntu2.7","7.35.0-1ubuntu2.8","7.35.0-1ubuntu2.9","7.35.0-1ubuntu2.10","7.35.0-1ubuntu2.11","7.35.0-1ubuntu2.12","7.35.0-1ubuntu2.13","7.35.0-1ubuntu2.14","7.35.0-1ubuntu2.15","7.35.0-1ubuntu2.16","7.35.0-1ubuntu2.17","7.35.0-1ubuntu2.19","7.35.0-1ubuntu2.20","7.35.0-1ubuntu2.20+esm2","7.35.0-1ubuntu2.20+esm3","7.35.0-1ubuntu2.20+esm4","7.35.0-1ubuntu2.20+esm5","7.35.0-1ubuntu2.20+esm6","7.35.0-1ubuntu2.20+esm7","7.35.0-1ubuntu2.20+esm8","7.35.0-1ubuntu2.20+esm9","7.35.0-1ubuntu2.20+esm10","7.35.0-1ubuntu2.20+esm11","7.35.0-1ubuntu2.20+esm12","7.35.0-1ubuntu2.20+esm13","7.35.0-1ubuntu2.20+esm14"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"7.35.0-1ubuntu2.20+esm15","binary_name":"curl"},{"binary_name":"libcurl3","binary_version":"7.35.0-1ubuntu2.20+esm15"},{"binary_name":"libcurl3-gnutls","binary_version":"7.35.0-1ubuntu2.20+esm15"},{"binary_name":"libcurl3-nss","binary_version":"7.35.0-1ubuntu2.20+esm15"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-27535.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/curl@7.47.0-1ubuntu2.19+esm8?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.47.0-1ubuntu2.19+esm8"}]}],"versions":["7.43.0-1ubuntu2","7.45.0-1ubuntu1","7.46.0-1ubuntu1","7.47.0-1ubuntu1","7.47.0-1ubuntu2","7.47.0-1ubuntu2.1","7.47.0-1ubuntu2.2","7.47.0-1ubuntu2.3","7.47.0-1ubuntu2.4","7.47.0-1ubuntu2.5","7.47.0-1ubuntu2.6","7.47.0-1ubuntu2.7","7.47.0-1ubuntu2.8","7.47.0-1ubuntu2.9","7.47.0-1ubuntu2.11","7.47.0-1ubuntu2.12","7.47.0-1ubuntu2.13","7.47.0-1ubuntu2.14","7.47.0-1ubuntu2.15","7.47.0-1ubuntu2.16","7.47.0-1ubuntu2.18","7.47.0-1ubuntu2.19","7.47.0-1ubuntu2.19+esm1","7.47.0-1ubuntu2.19+esm2","7.47.0-1ubuntu2.19+esm3","7.47.0-1ubuntu2.19+esm4","7.47.0-1ubuntu2.19+esm5","7.47.0-1ubuntu2.19+esm6","7.47.0-1ubuntu2.19+esm7"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"curl","binary_version":"7.47.0-1ubuntu2.19+esm8"},{"binary_name":"libcurl3","binary_version":"7.47.0-1ubuntu2.19+esm8"},{"binary_name":"libcurl3-gnutls","binary_version":"7.47.0-1ubuntu2.19+esm8"},{"binary_name":"libcurl3-nss","binary_version":"7.47.0-1ubuntu2.19+esm8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-27535.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/curl@7.58.0-2ubuntu3.24?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.58.0-2ubuntu3.24"}]}],"versions":["7.55.1-1ubuntu2","7.55.1-1ubuntu2.1","7.57.0-1ubuntu1","7.58.0-2ubuntu1","7.58.0-2ubuntu2","7.58.0-2ubuntu3","7.58.0-2ubuntu3.1","7.58.0-2ubuntu3.2","7.58.0-2ubuntu3.3","7.58.0-2ubuntu3.5","7.58.0-2ubuntu3.6","7.58.0-2ubuntu3.7","7.58.0-2ubuntu3.8","7.58.0-2ubuntu3.9","7.58.0-2ubuntu3.10","7.58.0-2ubuntu3.12","7.58.0-2ubuntu3.13","7.58.0-2ubuntu3.14","7.58.0-2ubuntu3.15","7.58.0-2ubuntu3.16","7.58.0-2ubuntu3.17","7.58.0-2ubuntu3.18","7.58.0-2ubuntu3.19","7.58.0-2ubuntu3.20","7.58.0-2ubuntu3.21","7.58.0-2ubuntu3.22","7.58.0-2ubuntu3.23"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"curl","binary_version":"7.58.0-2ubuntu3.24"},{"binary_name":"libcurl3-gnutls","binary_version":"7.58.0-2ubuntu3.24"},{"binary_version":"7.58.0-2ubuntu3.24","binary_name":"libcurl3-nss"},{"binary_name":"libcurl4","binary_version":"7.58.0-2ubuntu3.24"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-27535.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/curl@7.68.0-1ubuntu2.18?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.68.0-1ubuntu2.18"}]}],"versions":["7.65.3-1ubuntu3","7.65.3-1ubuntu4","7.66.0-1ubuntu1","7.67.0-2ubuntu1","7.68.0-1ubuntu1","7.68.0-1ubuntu2","7.68.0-1ubuntu2.1","7.68.0-1ubuntu2.2","7.68.0-1ubuntu2.4","7.68.0-1ubuntu2.5","7.68.0-1ubuntu2.6","7.68.0-1ubuntu2.7","7.68.0-1ubuntu2.10","7.68.0-1ubuntu2.11","7.68.0-1ubuntu2.12","7.68.0-1ubuntu2.13","7.68.0-1ubuntu2.14","7.68.0-1ubuntu2.15","7.68.0-1ubuntu2.16"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"curl","binary_version":"7.68.0-1ubuntu2.18"},{"binary_name":"libcurl3-gnutls","binary_version":"7.68.0-1ubuntu2.18"},{"binary_name":"libcurl3-nss","binary_version":"7.68.0-1ubuntu2.18"},{"binary_name":"libcurl4","binary_version":"7.68.0-1ubuntu2.18"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-27535.json"}},{"package":{"name":"curl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/curl@7.81.0-1ubuntu1.10?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.81.0-1ubuntu1.10"}]}],"versions":["7.74.0-1.3ubuntu2","7.74.0-1.3ubuntu3","7.80.0-3","7.81.0-1","7.81.0-1ubuntu1.1","7.81.0-1ubuntu1.2","7.81.0-1ubuntu1.3","7.81.0-1ubuntu1.4","7.81.0-1ubuntu1.6","7.81.0-1ubuntu1.7","7.81.0-1ubuntu1.8"],"ecosystem_specific":{"availability":"No subscription 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