--- id: CVE-2021-22898 title: >- curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers summary: >- curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser f… severity: low cvss: 3.1 cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N' cwe: - CWE-200 - CWE-909 vendor: haxx product: curl affected: - 'curl >= 7.7, <= 7.76.1' - debian_linux = 9.0 - fedora = 33 - fedora = 34 - communications_cloud_native_core_binding_support_function = 1.11.0 - >- communications_cloud_native_core_network_function_cloud_native_environment = 1.10.0 - communications_cloud_native_core_network_repository_function = 1.15.0 - communications_cloud_native_core_network_repository_function = 1.15.1 - communications_cloud_native_core_network_slice_selection_function = 1.8.0 - communications_cloud_native_core_service_communication_proxy = 1.15.0 - essbase < 11.1.2.4.047 - 'essbase >= 21.0, < 21.3' - mysql_server < 5.7.34 - 'mysql_server >= 8.0.15, < 8.0.25' - sinec_infrastructure_network_services < 1.0.1.1 - 'universal_forwarder >= 8.2.0, < 8.2.12' - 'universal_forwarder >= 9.0.0, < 9.0.6' - universal_forwarder = 9.1.0 patched: - essbase 21.3 - mysql_server 8.0.25 - sinec_infrastructure_network_services 1.0.1.1 - universal_forwarder 9.0.6 published: '2021-06-11' updated: '2026-10-14' sourceUpdated: '2026-10-14T11:16:52.873' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-22898' references: - url: 'http://www.openwall.com/lists/oss-security/2021/07/21/4' label: support@hackerone.com - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf' label: support@hackerone.com - url: 'https://curl.se/docs/CVE-2021-22898.html' label: support@hackerone.com - url: >- https://github.com/curl/curl/commit/39ce47f219b09c380b81f89fe54ac586c8db6bde label: support@hackerone.com - url: 'https://hackerone.com/reports/1176461' label: support@hackerone.com - url: >- https://lists.apache.org/thread.html/rc713534b10f9daeee2e0990239fa407e2118e4aa9e88a7041177497c%40%3Cissues.guacamole.apache.org%3E label: support@hackerone.com - url: 'https://lists.debian.org/debian-lts-announce/2021/08/msg00017.html' label: support@hackerone.com - url: 'https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html' label: support@hackerone.com - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/ label: support@hackerone.com - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/POOC3UV7V6L4CJ5KA2PTWTNUV5Y72T3Q/ label: support@hackerone.com - url: 'https://www.debian.org/security/2022/dsa-5197' label: support@hackerone.com - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: support@hackerone.com - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html' label: support@hackerone.com - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: support@hackerone.com - url: 'http://www.openwall.com/lists/oss-security/2021/07/21/4' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://curl.se/docs/CVE-2021-22898.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://github.com/curl/curl/commit/39ce47f219b09c380b81f89fe54ac586c8db6bde label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://hackerone.com/reports/1176461' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/rc713534b10f9daeee2e0990239fa407e2118e4aa9e88a7041177497c%40%3Cissues.guacamole.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2021/08/msg00017.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/ label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/POOC3UV7V6L4CJ5KA2PTWTNUV5Y72T3Q/ label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.debian.org/security/2022/dsa-5197' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd epss: 0.04507 epssPercentile: 0.91313 ingestedAt: '2026-10-14T11:27:22.124Z' --- ## Overview curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol. ## Affected - `curl >= 7.7, <= 7.76.1` - `debian_linux = 9.0` - `fedora = 33` - `fedora = 34` - `communications_cloud_native_core_binding_support_function = 1.11.0` - `communications_cloud_native_core_network_function_cloud_native_environment = 1.10.0` - `communications_cloud_native_core_network_repository_function = 1.15.0` - `communications_cloud_native_core_network_repository_function = 1.15.1` - `communications_cloud_native_core_network_slice_selection_function = 1.8.0` - `communications_cloud_native_core_service_communication_proxy = 1.15.0` - `essbase < 11.1.2.4.047` - `essbase >= 21.0, < 21.3` - `mysql_server < 5.7.34` - `mysql_server >= 8.0.15, < 8.0.25` - `sinec_infrastructure_network_services < 1.0.1.1` - `universal_forwarder >= 8.2.0, < 8.2.12` - `universal_forwarder >= 9.0.0, < 9.0.6` - `universal_forwarder = 9.1.0` ## Remediation Upgrade past the affected range: - `essbase 21.3` - `mysql_server 8.0.25` - `sinec_infrastructure_network_services 1.0.1.1` - `universal_forwarder 9.0.6`