CVE-2023-37897

Server-side Template Injection (SSTI) in grav

HIGH
8.8
CVSS Score
Published: July 18, 2023 at 08:22 PM UTC
Updated: June 17, 2026 at 06:08 AM UTC
1 product affected across 1 vendorGrav

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Severity
HIGH8.8
Exploit prediction
EPSS 3%
SSVC
PoC

Description

Grav is a file-based Web-platform built in PHP. Grav is subject to a server side template injection (SSTI) vulnerability. The fix for another SSTI vulnerability using `|map`, `|filter` and `|reduce` twigs implemented in the commit `71bbed1` introduces bypass of the denylist due to incorrect return value from `isDangerousFunction()`, which allows to execute the payload prepending double backslash (`\\`). The `isDangerousFunction()` check in version 1.7.42 and onwards retuns `false` value instead of `true` when the `\` symbol is found in the `$name`. This vulnerability can be exploited if the attacker has access to: 1. an Administrator account, or 2. a non-administrator, user account that has Admin panel access and Create/Update page permissions. A fix for this vulnerability has been introduced in commit `b4c6210` and is included in release version `1.7.42.2`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
v < 1.7.42.21.7.421.7.42.1
Affected range stops below 1.7.42.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-74CWE-393

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