CVE-2021-3531

A flaw was found in the Red Hat Ceph Storage RGW in versions before 14.2.21. When processing a GET Request for a swift URL that ends with two slashes it can cause the rgw to crash, resulting in a denial of service. The greatest threat to the system is of availability.

Published: 2021-05-18 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3531 is rated Low Risk (37.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.26%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3531

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 1.22% 0.26% -0.96%
2 2025-11-18 0.26% 1.22% +0.96%
3 2025-03-30 — 0.26% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3531

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-3531

OS Trackers for CVE-2021-3531

vendor priority summary link
alpine medium CVE-2021-3531: 2 source package rows (ceph, ceph16); 7 state rows across 3 repos (3.17-community, 3.18-community, edge-community); fixed 4, open 3. https://security.alpinelinux.org/vuln/CVE-2021-3531
debian not yet assigned CVE-2021-3531 not yet assigned priority: Debian including 1 source packages (ceph), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3531
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3531
suse high CVE-2021-3531 severity important: SUSE including 382 source package names (0.45.0.8.14.1:librados2-15.2.12.83+g528da226523-3.25.1, 0.45.0.8.14.1:librbd1-15.2.12.83+g528da226523-3.25.1, …), 810 product×package rows across 67 product lines (Container caasp/v4/hyperkube, Container ses/6/cephcsi/cephcsi, … (67 product lines)): Fixed 567, Known Not Affected 243. https://www.suse.com/security/cve/CVE-2021-3531/
ubuntu medium CVE-2021-3531 medium priority: Ubuntu including 1 source packages (ceph), 15 status rows across 15 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): released 13, not-affected 2. https://ubuntu.com/security/CVE-2021-3531

Affected software / configurations for CVE-2021-3531

Vendor Product Version Raw CPE
redhat ceph < 14.2.21 cpe:2.3:a:redhat:ceph:*:*:*:*:*:*:*:*
redhat ceph_storage 4.0 cpe:2.3:a:redhat:ceph_storage:4.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-3531

cvelogic Threat Intelligence