Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-34448 is a high-severity Improper Input Validation (CWE-20) vulnerability in Getgrav Grav. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Grav is a flat-file content management system that embeds the Twig templating engine. CVE-2023-34448 is an incomplete remediation of an earlier server-side template injection issue (CVE-2022-2073) that allowed use of the default filter() function. The flaw persisted in versions prior to 1.7.42 because other built-in Twig Core Extension functions, notably map() and reduce(), could still be abused to invoke arbitrary unsafe PHP functions, resulting in remote code execution. The affected code resides in Grav’s Twig integration layer.
An authenticated user with permission to supply or modify page content or templates can supply a crafted Twig expression that reaches these filters. Because the application processes the expression server-side with no additional sandboxing, the attacker can execute operating-system commands, read or modify files, and fully compromise the host. The CVSS 8.8 vector reflects network attack reachability, low complexity, and low privileges required.
The project’s security advisory and accompanying commits state that version 1.7.42 overrides map() and reduce() inside system/src/Grav/Common/Twig/Extension/GravExtension.php, inserting explicit validation of the callable argument passed via the $arrow variable. Administrators are advised to upgrade immediately; no other configuration changes are documented.
EPSS for the CVE has remained flat at 0.0885 with no material increase after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-1902
Vulnerability Data
Grav is a flat-file content management system. Prior to version 1.7.42, the patch for CVE-2022-2073, a server-side template injection vulnerability in Grav leveraging the default `filter()` function, did not block other built-in functions exposed by Twig's Core Extension that could…
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be used to invoke arbitrary unsafe functions, thereby allowing for remote code execution. A patch in version 1.74.2 overrides the built-in Twig `map()` and `reduce()` filter functions in `system/src/Grav/Common/Twig/Extension/GravExtension.php` to validate the argument passed to the filter in `$arrow`.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.7V1.3.10V1.3.1
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Directly implements checks on information inputs to reject invalid data before processing.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.
Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.
Directly prevents execution of attacker-supplied code written into data memory regions.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).
PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-20, a class-level weakness, and none of its children carries one either.