# What is CVE-2017-5644?

> CVE-2017-5644 is a medium-severity flaw (CVSS 5.5) in Poi from Apache, published on 24 March 2017. 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 4.6%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2017-5644

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 19 out of 100 (Info); action: Track. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 5.5 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 4.6% (latest exploit-likelihood forecast)
- **Published:** 24 March 2017
- **Record last updated:** 20 April 2025
- **Main product:** Poi from Apache
- **Affected products:** 1

## What is CVE-2017-5644? In plain terms

An attacker has to be already on the device without logging in, but a person has to take an action first. If it works, the attacker can take it offline.

### The official description

Apache POI in versions prior to release 3.15 allows remote attackers to cause a denial of service (CPU consumption) via a specially crafted OOXML file, aka an XML Entity Expansion (XEE) attack.

### What kind of flaw is it?

- CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

### How an attack on it works

- Where an attacker can be: Already on the device
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: Yes, a person has to take an action
- What an attacker gets: Can take it offline

Severity vector: `CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`

## Is CVE-2017-5644 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 4.6%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 4.6%, 4.6%, 4.6%, 4.6%, 4.6%, 4.6%, 4.6%.

### Timeline

- 24 March 2017: Published
- 20 April 2025: Record last updated

### How Precursor Intelligence ranks it

CVE-2017-5644 scores **19 out of 100 (Info)**, with the action "Track".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2017-5644?

The published record lists 1 product.

- [Poi](https://www.precursorintelligence.com/product/apache/poi) by [Apache](https://www.precursorintelligence.com/vendors/apache) (Application): up to 3.14

## How do I fix CVE-2017-5644?

1. **Check whether you run it.** Compare 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 fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow 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 it.** Track 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

- [poi.apache.org](http://poi.apache.org/#20+March+2017+-+CVE-2017-5644+-+Possible+DOS+%28Denial+of+Service%29+in+Apache+POI+versions+prior+to+3.15) (Vendor advisory)
- [securityfocus.com](http://www.securityfocus.com/bid/96983)
- [oracle.com](https://www.oracle.com/security-alerts/cpuoct2020.html)

## Questions

### What is CVE-2017-5644?

CVE-2017-5644 is a medium-severity flaw in Poi from Apache, published on 24 March 2017. An attacker has to be already on the device without logging in, but a person has to take an action first. If it works, the attacker can take it offline.

### How serious is CVE-2017-5644?

It scores 5.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2017-5644 is 19 out of 100, which is Info. Its action is "Track". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2017-5644 being exploited?

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 4.6%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2017-5644 affect?

For Poi from Apache: up to 3.14.

### How do I fix CVE-2017-5644?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2017-5644 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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