cbcvebase.
CVE-2021-3654
published 2022-03-02

CVE-2021-3654: A vulnerability was found in openstack-nova's console proxy, noVNC. By crafting a malicious URL, noVNC could be made to redirect to any desired URL.

PriorityP347medium6.1CVSS 3.1
AVNACLPRNUIRSCCLILAN
EXPLOIT
EPSS
26.79%
97.8th percentile
A vulnerability was found in openstack-nova's console proxy, noVNC. By crafting a malicious URL, noVNC could be made to redirect to any desired URL.

Affected

15 ranges
VendorProductVersion rangeFixed in
debiannova< nova 2:23.0.2-3 (bookworm)nova 2:23.0.2-3 (bookworm)
openstacknova< 21.2.321.2.3
openstacknova>= 0 < 2:23.0.2-32:23.0.2-3
openstacknova>= 0 < 2:23.0.2-32:23.0.2-3
openstacknova>= 0 < 2:23.0.2-32:23.0.2-3
openstacknova>= 0 < 21.2.321.2.3
openstacknova>= 0 < 2:17.0.13-0ubuntu5.32:17.0.13-0ubuntu5.3
openstacknova>= 0 < 2:21.2.4-0ubuntu2.22:21.2.4-0ubuntu2.2
openstacknova>= 0 < 2:13.1.4-0ubuntu4.5+esm12:13.1.4-0ubuntu4.5+esm1
openstacknova>= 22.0.0 < 22.2.322.2.3
openstacknova>= 22.0.0 < 22.2.322.2.3
openstacknova>= 23.0.0 < 23.0.323.0.3
openstacknova>= 23.0.0 < 23.0.323.0.3
redhatopenstack_platform
redhatopenstack_platform

Detection & IOCsextracted from sources · hover to see the quote

url{{BaseURL}}//interact.sh/%2f..
yara
regex: '(?m)^(?:Location\s*?:\s*?)(?:https?://|//)?(?:[a-zA-Z0-9\-_\.@]*)interact\.sh.*$'
  • Detect open redirect exploitation attempts against noVNC proxy by looking for HTTP requests containing a double-slash followed by an external domain and a URL-encoded path traversal sequence (e.g., `//interact.sh/%2f..`) in the request URI.
  • Alert on HTTP 301/302 redirect responses from the noVNC proxy where the Location header resolves to an external/unexpected domain, indicating a successful open redirect.
  • The vulnerability originates from improper URL validation in noVNC's console proxy; monitor noVNC proxy logs for requests with double-slash (`//`) prefixed hostnames or URL-encoded path traversal (`%2f..`) patterns that could be used to craft a malicious redirect.
  • The root cause is in CPython's URL handling (see bugs.python.org/issue32084); environments using affected CPython versions with openstack-nova noVNC proxy are at risk regardless of Nova version.
  • ·This vulnerability only affected Ubuntu 16.04 ESM and Ubuntu 18.04 LTS according to Ubuntu's security notice; Ubuntu 20.04 LTS and later are not listed as affected for CVE-2021-3654.
  • ·On Debian, the vulnerability remains open in bullseye but is resolved in bookworm, forky, sid, and trixie (fixed in 2:23.0.2-3); detection/patching scope should be scoped accordingly.
  • ·Red Hat OpenStack Platform 10 (Newton) and 13 (Queens) are listed as out of support scope; no mitigation meeting Red Hat's criteria is available for affected RHOSP versions.

CVSS provenance

nvdv3.16.1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvdv2.04.0MEDIUMAV:N/AC:H/Au:N/C:P/I:P/A:N
osv6.1MEDIUM
vendor_debian6.1MEDIUM
vendor_redhat6.1MEDIUM
vendor_ubuntu3.3LOW
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