CVE-2021-3312

Exp

An XML external entity (XXE) vulnerability in Alkacon OpenCms 11.0, 11.0.1 and 11.0.2 allows remote authenticated users with edit privileges to exfiltrate files from the server's file system by uploading a crafted SVG document.

Published: 2021-10-08 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3312 is rated High Exploit Risk (60.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.34%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2021-3312

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-3312

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 2026-03-02 0.48% 0.34% -0.14%
2 2025-11-21 0.34% 0.48% +0.14%
3 2025-11-18 — 0.34% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3312

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N 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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N 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:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-3312

GitHub Security Advisory for CVE-2021-3312

GHSA-g6v7-vqhx-6v6c · Severity: medium · Ecosystem: maven — XML External Entity Reference in org.opencms:opencms-core

Affected software / configurations for CVE-2021-3312

Vendor Product Version Raw CPE
alkacon opencms 11.0 cpe:2.3:a:alkacon:opencms:11.0:-:*:*:*:*:*:*
alkacon opencms 11.0.1 cpe:2.3:a:alkacon:opencms:11.0.1:*:*:*:*:*:*:*
alkacon opencms 11.0.2 cpe:2.3:a:alkacon:opencms:11.0.2:*:*:*:*:*:*:*

References for CVE-2021-3312

URL Tags
https://github.com/alkacon/opencms-core/issues/725 Exploit Issue Tracking Third Party Advisory
https://github.com/alkacon/opencms-core/releases Release Notes Third Party Advisory
cvelogic Threat Intelligence