CVE-2020-1760

A flaw was found in the Ceph Object Gateway, where it supports request sent by an anonymous user in Amazon S3. This flaw could lead to potential XSS attacks due to the lack of proper neutralization of untrusted input.

Red Hat OpenStack Platform 15 (RHOSP) packages Ceph but no longer uses it, instead pulling ceph directly from the Red Hat Ceph Storage 4 repository. For this reason, RHOSP will not be updated for this flaw.

This issue affects the versions of ceph as shipped with Red Hat Ceph Storage 3, 4 and Red Hat Openshift Container Storage 4.2 as it allows unauthenticated requests sent by an anonymous user for Amazon S3.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

• Mitigation provided by DigitalOcean:

Mitigation relies on the HAProxy load-balancers in front of RGW, and uses HAProxy ACLs combined with in-house Lua embedded in HAProxy.

1. Detect usage of the query-parameters without any signature (either pre-signed or header), and return S3-formatted error.
2. Validate the content in the query-parameters, return S3-formatted error.

HAProxy mitigation:

acl req_s3_GetObject REDACTED ## redacted uses internal Lua to detect GetObject acl has_accesskey REDACTED ## redacted uses internal Lua to detect & validate signature

detection 1, QPs present

acl req_s3_GetObject_urlp_response url_param(response-cache-control) -m found acl req_s3_GetObject_urlp_response url_param(response-expires) -m found acl req_s3_GetObject_urlp_response url_param(response-content-disposition) -m found acl req_s3_GetObject_urlp_response url_param(response-content-encoding) -m found acl req_s3_GetObject_urlp_response url_param(response-content-language) -m found acl req_s3_GetObject_urlp_response url_param(response-content-type) -m found

detection 2, QPs containing unprintable ascii incl CRLR

acl req_s3_GetObject_urlp_response_crlf url_param(response-cache-control) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f acl req_s3_GetObject_urlp_response_crlf url_param(response-expires) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f acl req_s3_GetObject_urlp_response_crlf url_param(response-content-disposition) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f acl req_s3_GetObject_urlp_response_crlf url_param(response-content-encoding) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f acl req_s3_GetObject_urlp_response_crlf url_param(response-content-language) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f acl req_s3_GetObject_urlp_response_crlf url_param(response-content-type) -m sub -i %00 %01 %02 %03 %04 %05 %06 %07 %08 %09 %0a %0b %0c %0d %0e %0f %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f

block for detection 1

http-request use-service lua.REDACTED if req_s3_GetObject req_s3_GetObject_urlp_response !has_accesskey

block for detection 2

http-request use-service lua.REDACTED if req_s3_GetObject req_s3_GetObject_urlp_response_crlf