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9.8
CRITICAL CVSS 3.1
CVE-2021-41170
Neoan3-Apps/Template Unauthorized Code Execution Vulnerability
Description

neoan3-apps/template is a neoan3 minimal template engine. Versions prior to 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously. In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible. Version 1.1.1 has addressed this vulnerability. Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade.

INFO

Published Date :

Nov. 8, 2021, 7:15 p.m.

Last Modified :

Nov. 21, 2024, 6:25 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Affected Products

The following products are affected by CVE-2021-41170 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Neoan neoan3-template
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 HIGH [email protected]
CVSS 3.1 CRITICAL [email protected]
CVSS 3.1 CRITICAL [email protected]
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-41170.

URL Resource
https://github.com/sroehrl/neoan3-template/commit/4a2c9570f071d3c8f4ac790007599cba20e16934 Patch Third Party Advisory
https://github.com/sroehrl/neoan3-template/issues/8 Issue Tracking Patch Third Party Advisory
https://github.com/sroehrl/neoan3-template/security/advisories/GHSA-3v56-q6r6-4gcw Patch Third Party Advisory
https://github.com/sroehrl/neoan3-template/commit/4a2c9570f071d3c8f4ac790007599cba20e16934 Patch Third Party Advisory
https://github.com/sroehrl/neoan3-template/issues/8 Issue Tracking Patch Third Party Advisory
https://github.com/sroehrl/neoan3-template/security/advisories/GHSA-3v56-q6r6-4gcw Patch Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-41170 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-41170 weaknesses.

CAPEC-3: Using Leading 'Ghost' Character Sequences to Bypass Input Filters Using Leading 'Ghost' Character Sequences to Bypass Input Filters CAPEC-6: Argument Injection Argument Injection CAPEC-7: Blind SQL Injection Blind SQL Injection CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-28: Fuzzing Fuzzing CAPEC-34: HTTP Response Splitting HTTP Response Splitting CAPEC-42: MIME Conversion MIME Conversion CAPEC-43: Exploiting Multiple Input Interpretation Layers Exploiting Multiple Input Interpretation Layers CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-51: Poison Web Service Registry Poison Web Service Registry CAPEC-52: Embedding NULL Bytes Embedding NULL Bytes CAPEC-53: Postfix, Null Terminate, and Backslash Postfix, Null Terminate, and Backslash CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-71: Using Unicode Encoding to Bypass Validation Logic Using Unicode Encoding to Bypass Validation Logic CAPEC-72: URL Encoding URL Encoding CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-78: Using Escaped Slashes in Alternate Encoding Using Escaped Slashes in Alternate Encoding CAPEC-79: Using Slashes in Alternate Encoding Using Slashes in Alternate Encoding CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic Using UTF-8 Encoding to Bypass Validation Logic CAPEC-83: XPath Injection XPath Injection CAPEC-84: XQuery Injection XQuery Injection CAPEC-101: Server Side Include (SSI) Injection Server Side Include (SSI) Injection CAPEC-105: HTTP Request Splitting HTTP Request Splitting CAPEC-108: Command Line Execution through SQL Injection Command Line Execution through SQL Injection CAPEC-120: Double Encoding Double Encoding CAPEC-135: Format String Injection Format String Injection CAPEC-250: XML Injection XML Injection CAPEC-267: Leverage Alternate Encoding Leverage Alternate Encoding CAPEC-273: HTTP Response Smuggling HTTP Response Smuggling CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs Accessing Functionality Not Properly Constrained by ACLs CAPEC-17: Using Malicious Files Using Malicious Files CAPEC-60: Reusing Session IDs (aka Session Replay) Reusing Session IDs (aka Session Replay) CAPEC-61: Session Fixation Session Fixation CAPEC-62: Cross Site Request Forgery Cross Site Request Forgery CAPEC-122: Privilege Abuse Privilege Abuse CAPEC-127: Directory Indexing Directory Indexing CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels Exploiting Incorrectly Configured Access Control Security Levels CAPEC-206: Signing Malicious Code Signing Malicious Code CAPEC-234: Hijacking a privileged process Hijacking a privileged process CAPEC-642: Replace Binaries Replace Binaries

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-41170 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2021-41170 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://github.com/sroehrl/neoan3-template/commit/4a2c9570f071d3c8f4ac790007599cba20e16934
    Added Reference https://github.com/sroehrl/neoan3-template/issues/8
    Added Reference https://github.com/sroehrl/neoan3-template/security/advisories/GHSA-3v56-q6r6-4gcw
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Nov. 17, 2021

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 15, 2021

    Action Type Old Value New Value
    Changed Description ### Impact Versions prior 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously. In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible. ### Patches Version 1.1.1 has addressed this vulnerability. ```php $params = [ 'reverse' => fn($input) => strrev($input), // <-- no longer possible with version ~1.1.1 'value' => 'My website' ] TemplateFunctions::registerClosure('reverse', fn($input) => strrev($input)); // <-- still possible (and nicely isolated) Template::embrace('<h1>{{reverse(value)}}</h1>', $params); ``` ### Workarounds Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade. ### References As a possible exploit is relatively easy to achieve, I will not share steps to reproduce the issue for now. ### For more information If you have any questions or comments about this advisory: * Open an issue in [our repo](https://github.com/sroehrl/neoan3-template) neoan3-apps/template is a neoan3 minimal template engine. Versions prior to 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously. In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible. Version 1.1.1 has addressed this vulnerability. Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade.
    Removed CVSS V3.1 GitHub, Inc. AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    Added CVSS V3.1 GitHub, Inc. AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Removed CVSS V3.1 Reason A-No limiting factors
    Removed CVSS V3.1 Reason C-No limiting factors
    Added CWE GitHub, Inc. CWE-74
  • Initial Analysis by [email protected]

    Nov. 13, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://github.com/sroehrl/neoan3-template/commit/4a2c9570f071d3c8f4ac790007599cba20e16934 No Types Assigned https://github.com/sroehrl/neoan3-template/commit/4a2c9570f071d3c8f4ac790007599cba20e16934 Patch, Third Party Advisory
    Changed Reference Type https://github.com/sroehrl/neoan3-template/issues/8 No Types Assigned https://github.com/sroehrl/neoan3-template/issues/8 Issue Tracking, Patch, Third Party Advisory
    Changed Reference Type https://github.com/sroehrl/neoan3-template/security/advisories/GHSA-3v56-q6r6-4gcw No Types Assigned https://github.com/sroehrl/neoan3-template/security/advisories/GHSA-3v56-q6r6-4gcw Patch, Third Party Advisory
    Added CWE NIST CWE-732
    Added CPE Configuration OR *cpe:2.3:a:neoan:neoan3-template:*:*:*:*:*:*:*:* versions up to (excluding) 1.1.1
  • CVE Modified by [email protected]

    Nov. 08, 2021

    Action Type Old Value New Value
    Changed Description ### Impact Versions prior 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously. In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible. ### Patches Version 1.1.1 has addressed this vulnerability. ```php $params = [ 'reverse' => fn($input) => strrev($input), // <-- no longer possible with version ~1.1.1 'value' => 'My website' ] TemplateFunctions::registerClosure('reverse', fn($input) => strrev($input)); // <-- still possible (and nicely isolated) Template::embrace('<h1>{{reverse(value)}}</h1>', $params); ``` ### Workarounds Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade. ### References As a possible exploit is relatively easy to achieve, I will not share steps to reproduce the issue for now. ### For more information If you have any questions or comments about this advisory: * Open an issue in [our repo](https://github.com/sroehrl/neoan3-template) ### Impact Versions prior 1.1.1 have allowed for passing in closures directly into the template engine. As a result values that are callable are executed by the template engine. The issue arises if a value has the same name as a method or function in scope and can therefore be executed either by mistake or maliciously. In theory all users of the package are affected as long as they either deal with direct user input or database values. A multi-step attack on is therefore plausible. ### Patches Version 1.1.1 has addressed this vulnerability. ```php $params = [ 'reverse' => fn($input) => strrev($input), // <-- no longer possible with version ~1.1.1 'value' => 'My website' ] TemplateFunctions::registerClosure('reverse', fn($input) => strrev($input)); // <-- still possible (and nicely isolated) Template::embrace('<h1>{{reverse(value)}}</h1>', $params); ``` ### Workarounds Unfortunately only working with hardcoded values is safe in prior versions. As this likely defeats the purpose of a template engine, please upgrade. ### References As a possible exploit is relatively easy to achieve, I will not share steps to reproduce the issue for now. ### For more information If you have any questions or comments about this advisory: * Open an issue in [our repo](https://github.com/sroehrl/neoan3-template)
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 7.5
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.52 }} 0.03%

score

0.65769

percentile