CVE-2013-0340: XEE

Published Aug 22, 2013
·
Updated

As reported on oss-security [1]:

So here are the CVE's for the two big ones, libxml2 and expat. Both are affected by the expansion of internal entities (which can be used to consume resources) and external entities (which can cause a denial of service against other services, be used to port scan, etc.).

To be clear:

==================== Internal entity expansion refers to the exponential/quadratic/fast linear expansion of XML entities, e.g.: ==================== <!DOCTYPE xmlbomb [ <!ENTITY a "1234567890" > <!ENTITY b "&a;&a;&a;&a;&a;&a;&a;&a;"> <!ENTITY c "&b;&b;&b;&b;&b;&b;&b;&b;"> <!ENTITY d "&c;&c;&c;&c;&c;&c;&c;&c;"> ]> <bomb>&d;</bomb>

or

<!DOCTYPE bomb [ <!ENTITY a "xxxxxxx... a couple of ten thousand chars"> ]> <bomb>&a;&a;&a;... repeat</bomb>

Which causes resources to be consumed

... Please use CVE-2013-0340 for expat internal entity expansion

[1] http://www.openwall.com/lists/oss-security/2013/02/22/4

Other sources

expat 2.1.0 and earlier does not properly handle entities expansion unless an application developer uses the XMLSetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HTTP requests to intranet servers, or read arbitrary files via a crafted XML document, aka an XML External Entity (XXE) issue. NOTE: it could be argued that because expat already provides the ability to disable external entity expansion, the responsibility for resolving this issue lies with application developers; according to this argument, this entry should be REJECTed, and each affected application would need its own CVE.

expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XMLSetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HTTP requests to intranet servers, or read arbitrary files via a crafted XML document, aka an XML External Entity (XXE) issue. NOTE: it could be argued that because expat already provides the ability to disable external entity expansion, the responsibility for resolving this issue lies with application developers; according to this argument, this entry should be REJECTed, and each affected application would need its own CVE.

MITRE

libexpat. This issue was addressed by updating expat to version 2.4.1.

Credit

an anonymous researcher

Affected Software

18 affected componentsFixes available
Apple macOS Big Sur<11.6
11.6
Apple tvOS<15
15
Apple Catalina
Apple WatchOS<8
8
Apple iOS<14.8
14.8
Apple iPadOS<14.8
14.8
Apple iOS<15
15
Apple iPadOS<15
15
Libexpat Project Libexpat<2.4.0
Python Python>=3.6.0<3.6.15
Python Python>=3.7.0<3.7.12
Python Python>=3.8.0<3.8.12
Python Python>=3.9.0<3.9.7
Apple iPadOS<14.8
Apple iPhone OS<14.8
Apple macOS<11.6
Apple tvOS<15.0
Apple WatchOS<8.0

Event History

Aug 22, 2013
Data Sourced
via Red Hat·05:30 PM
DescriptionSeverityAffected Software
Jan 21, 2014
CVE Published
via MITRE·06:00 PM
Data Sourced
via MITRE·06:00 PM
Description
Rejected
06:55 PM
Data Sourced
via NVD·06:55 PM
DescriptionSeverityWeaknessAffected Software
Nov 25, 2025
Rejected
via NVD·05:15 PM

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the vulnerability ID?

The vulnerability ID is CVE-2013-0340.

2

What is the affected software?

The affected software includes Apple watchOS, Apple macOS Big Sur, Apple iOS, Apple iPadOS, Apple Catalina, and Apple tvOS.

3

What is the remedy for Apple watchOS?

The remedy for Apple watchOS is to update to version 8 or later.

4

What is the remedy for Apple macOS Big Sur?

The remedy for Apple macOS Big Sur is to update to version 11.6 or later.

5

What is the remedy for Apple iOS and iPadOS?

The remedy for Apple iOS and iPadOS is to update to version 15 or later.

6

What is the remedy for Apple Catalina?

No specific remedy is mentioned for Apple Catalina.

7

What is the remedy for Apple tvOS?

The remedy for Apple tvOS is to update to version 15 or later.

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