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What is CVE-2013-0340?A medium-severity flaw in Libexpat, explained.

Medium severity7 affected products
The short answer

CVE-2013-0340 is a medium-severity flaw (CVSS 6.8) in Libexpat from Libexpat Project, published on 21 January 2014. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 19%. If you run an affected version, plan in the vendor’s fix.

Check if it affects you →How to fix it

Published 21 January 2014. Record last updated 11 April 2025. We keep this page's data up to date.

What it does

What is CVE-2013-0340? In plain terms.

It can be attacked from anywhere on the internet without logging in. If it works, the attacker can read some data, change some data and slow it down.

The official description

expat 2.1.0 and earlier does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler 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.

What kind of flaw is it?

  • CWE-611Improper Restriction of XML External Entity Reference
CVSS 2.0 scoreMedium · 6.8

How an attack on it works

Read straight from its severity rating, translated out of the shorthand.

  • Where an attacker can beAnywhere on the internet
  • How hard it is to pull offSome conditions needed
  • Login needed firstNo login needed
  • What an attacker getsCan read some data, change some data and slow it down

Severity vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

Exploitation

Is CVE-2013-0340 being exploited? Not that we know of.

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 19%. That can change at any time, which is why we keep watching.

Known to be exploitedNoNot on the list of exploited flaws today
Chance of use in the next 30 days19%Its EPSS score, from the latest forecast

Timeline

  1. Published
  2. Record last updated
  3. Exploit likelihood jumped
How Precursor Intelligence ranks it
43out of 100Medium

CVE-2013-0340 scores 43. Action: Plan remediation.

We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:

  • Evidence it is being exploitedBiggest factor
  • How severe it isStrong factor
  • How widely exposed it isSmaller factor
  • Threat activity around itSmaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.

When CVE-2013-0340 matches software you track, it lands in your list with its score and the reasons behind it.

See your own ranked list →
Affected products

Who is affected by CVE-2013-0340? 7 products.

The published record lists 7 products from 3 vendors. Versions are shown as published: "before 2.4.0" means every version up to, but not including, 2.4.0. If you run one of these, check your version, then go to the fix below.

  • Application

    Libexpat

    by Libexpat Project

    Affected versions
    before 2.4.0
  • Application

    Python

    by Python

    Affected versions
    3.6.0 to before 3.6.153.7.0 to before 3.7.123.8.0 to before 3.8.123.9.0 to before 3.9.7
  • Operating system

    iPadOS

    by Apple

    Affected versions
    before 14.8
  • Operating system

    iOS

    by Apple

    Affected versions
    before 14.8
  • Operating system

    macOS

    by Apple

    Affected versions
    before 11.6
  • Operating system

    tvOS

    by Apple

    Affected versions
    before 15.0
  • Operating system

    watchOS

    by Apple

    Affected versions
    before 8.0
Remediation

How do I fix CVE-2013-0340? Four steps.

  1. Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
  2. Apply the vendor’s fixInstall the latest update from the vendor. The references list where the vendor has published details.
  3. If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
  4. Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

References

24 links
Precursor Intelligence

Does CVE-2013-0340 affect you? We'll keep checking.

Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.

  1. Tell us what you runPick your software from a list, or let us work it out from your website.
  2. We match it to every flawOver 400,000 published flaws, checked against your list.
  3. Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
  4. Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
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Common questions, answered plainly.

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CVE-2013-0340 is a medium-severity flaw in Libexpat from Libexpat Project, published on 21 January 2014. It can be attacked from anywhere on the internet without logging in. If it works, the attacker can read some data, change some data and slow it down.

It scores 6.8 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2013-0340 is 43 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 19%. That can change at any time, which is why we keep watching.

For Libexpat from Libexpat Project: before 2.4.0. The record lists 7 products in all, each with its versions, under "Who is affected" on this page.

Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

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