CVE-2021-3312

MEDIUM

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 upl...

Affects 1 product across 1 vendor.

CVSS 3.16.5
EPSS1.3%
Percentile70th
PatchUnknown
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, low privileges required, no user interaction needed, impact contained to the vulnerable component, full confidentiality impact, no integrity impact, no availability impact.
CWE Weakness Definitions
CWE-611: CWE-611
Related Attack Patterns (CAPEC)
CAPEC-221 Data Serialization External Entities Blowup
via CWE-611

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ AI Analysis — automated analysis, not human-reviewed

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.

BSID: BS-2021-GLOBAL-306665-M • Model: /workspace/models/qwen2.5-coder-32b-instruct-bf16 • Confidence: MEDIUM

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Frequently Asked Questions
What is CVE-2021-3312?
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.
What is the CVSS score for CVE-2021-3312?
CVE-2021-3312 has CVSS 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N. EPSS: 1.3%.
Is CVE-2021-3312 actively exploited?
No confirmed active exploitation of CVE-2021-3312 as of 2026-09-25.
How do I remediate CVE-2021-3312?
Priority: HIGH.
What systems are affected by CVE-2021-3312?
CVE-2021-3312 affects Alkacon Opencms.
Vulnerability Details
CVE IDCVE-2021-3312
BSIDBS-2021-GLOBAL-306665-M BreachSpider Global ID
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Published2021-10-08
Last Modified2026-06-17
ICS Relevance0%
Weakness (CWE)
CWE-611
SourceNVD
Official Description

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.

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

The vulnerability is exploited by uploading a specially crafted SVG file that contains an XML external entity declaration. This allows the attacker to read arbitrary files on the server where OpenCms is installed.

Exploitation Likelihood: MEDIUM

Affected Products
VendorProductAffected Versions
Alkacon Opencms 11.0 11.0.1 11.0.2
Remediation

No official vendor advisory link on record. See the CVE record →

Threat Intelligence
● Threat Intelligence Validated: October 2026 | Threat Age: 1833 Days
CISA known-exploitedNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
AI Enrichment Record — provenance & audit hash
Model/workspace/models/qwen2.5-coder-32b-instruct-bf16
ConfidenceMEDIUM
Enriched At2026-05-24
SHA-512 Audit Hash987aa617e26512e410a74bd36b3a5020dbe4431a6d4e457a9000764a4be993f10ee53eda5e4d069d25645f20a1127bbc0a04d511d7f4b69a91063ee99f6ed139
Related CVEs affecting Alkacon
CVE-2018-8811 8.8 Cross-site request forgery (CSRF) vulnerability in system/workplace/admin/acc... CVE-2019-11819 7.8 Alkacon OpenCMS v10.5.4 and before is affected by CSV (aka Excel Macro) Injec... CVE-2023-42346 7.5 Alkacon OpenCms before 16 allows XXE when the <!DOCTYPE> refers to an external host. CVE-2023-42344 7.3 Alkacon OpenCms before 10.5.1 allows remote unauthenticated attackers to obta... CVE-2005-4475 6.8 Cross-site scripting (XSS) vulnerability in OpenCms 6.0.3 and earlier allows ...
View all Alkacon CVEs →

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