It was found that libcurl might accidentally leak authentication data to third parties. When asked to send custom headers in its HTTP requests, libcurl will send that set of headers first to the host in the initial URL but also, if asked to follow redirects and a 30X HTTP response code is returned, to the host mentioned in URL in the `Location:` response header value. Sending the same set of headers to subsequest hosts is in particular a problem for applications that pass on custom `Authorization:` headers, as this header often contains privacy sensitive information or data that could allow others to impersonate the libcurl-using client's request. This bug has existed since before curl 6.0.
Acknowledgments: Name: the Curl project Upstream: Craig de Stigter
Created attachment 1384445 [details] Upstream patch
External References: https://curl.haxx.se/docs/adv_2018-b3bf.html
Created curl tracking bugs for this issue: Affects: fedora-all [bug 1537968] Created mingw-curl tracking bugs for this issue: Affects: epel-7 [bug 1537966] Affects: fedora-all [bug 1537967]
Ceph uses libcurl in the rados gateway (RGW) only. By default CURLOPT_FOLLOWLOCATION is disabled and thus 3xx are returned rather than followed (https://curl.haxx.se/libcurl/c/CURLOPT_FOLLOWLOCATION.html). RGW does not override default, and thus is not vulnerable.
Mitigation: By default, curl and libcurl will not follow redirect requests. This flaw happens only when curl or libcurl are explicitly requested to follow redirects (option --location in curl, and CURLOPT_FOLLOWLOCATION in libcurl). To mitigate this, it is possible to prevent the automated following of redirects, replacing it by manual redirects (and remove the authentication header), for example.
Statement: This issue affects the versions of curl as shipped with Red Hat Enterprise Linux 5, 6, and 7, as well as the versions of httpd24-curl as shipped with Red Hat Software Collections. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2018:3157 https://access.redhat.com/errata/RHSA-2018:3157
This issue has been addressed in the following products: Red Hat Software Collections for Red Hat Enterprise Linux 6 Red Hat Software Collections for Red Hat Enterprise Linux 7 Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS Via RHSA-2018:3558 https://access.redhat.com/errata/RHSA-2018:3558
This issue has been addressed in the following products: JBoss Core Services Apache HTTP Server 2.4.29 SP2 Via RHSA-2019:1543 https://access.redhat.com/errata/RHSA-2019:1543
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.5 Extended Update Support Via RHSA-2020:0544 https://access.redhat.com/errata/RHSA-2020:0544
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.4 Advanced Update Support Red Hat Enterprise Linux 7.4 Update Services for SAP Solutions Red Hat Enterprise Linux 7.4 Telco Extended Update Support Via RHSA-2020:0594 https://access.redhat.com/errata/RHSA-2020:0594