CVE-2021-29439 | Plugins can be installed with minimal admin privileges

The Grav admin plugin prior to version 1.10.11 does not correctly verify caller's privileges. As a consequence, users with the permission `admin.login` can install third-party plugins and their dependencies. By installing the right plugin, an attacker can obtain an arbitrary code execution primitive and elevate their privileges on the instance. The vulnerability has been addressed in version 1.10.11. As a mitigation blocking access to the `/admin` path from untrusted sources will reduce the probability of exploitation.

Published: 2021-04-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-29439 is rated Moderate Risk (54.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.72%). Mandatory action: Review affected assets and schedule remediation.

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-2021-29439

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 2025-12-14 0.32% 0.72% +0.40%
2 2025-11-21 0.72% 0.32% -0.40%
3 2025-11-18 0.72%

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29439

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.2 5.9 [email protected]
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.2 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/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:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.0 6.4 [email protected]

Weakness enumeration for CVE-2021-29439

Affected software / configurations for CVE-2021-29439

Vendor Product Version Raw CPE
getgrav grav_admin < 1.10.11 cpe:2.3:a:getgrav:grav_admin:*:*:*:*:*:*:*:*

References for CVE-2021-29439

cvelogic Threat Intelligence