CVE-2023-34253Public exploitNetwork attack vector

Authenticated code execution via template denylist bypass

Published Jun 14, 2023 · Updated Dec 18, 2024

Server-side template injection in GetGrav Grav before 1.7.42 allows remote authenticated users to execute arbitrary code through page content. Utils::isDangerousFunction compares attacker-supplied callable names against an incomplete, case-sensitive denylist without rejecting fully qualified names. Access to the Admin panel with page creation or update rights is required, after which crafted Twig content executes with the web process's privileges.

CVSS severity8.8
High
EPSS probability2.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side template injection in GetGrav Grav before 1.7.42 allows remote authenticated users to execute arbitrary code through page content. Utils::isDangerousFunction compares attacker-supplied callable names against an incomplete, case-sensitive denylist without rejecting fully qualified names. Access to the Admin panel with page creation or update rights is required, after which crafted Twig content executes with the web process's privileges.

The record

CVE
CVE-2023-34253
Published
Jun 14, 2023
Updated
Dec 18, 2024
Vendor
GetGrav
Product
Grav
Classifications
CWE-1336, CWE-184, CWE-94, T1190, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 18, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.7.42

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GetGrav · Gravversion=< 1.7.42

Published CVSS scores

8.8GitHub, Inc. CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2GetGrav security advisoryCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
CWE-184Incomplete List of Disallowed Inputs
CWE-94Improper Control of Generation of Code ('Code Injection')
T1190Exploit Public-Facing Application
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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