CVE-2017-9047

What it is

A buffer overflow was discovered in libxml2 20904-GITv2.9.4-16-g0741801. The function xmlSnprintfElementContent in valid.c is supposed to recursively dump the element content definition into a char buffer 'buf' of size 'size'. The variable len is assigned strlen(buf). If the content->type is XML_ELEMENT_CONTENT_ELEMENT, then (i) the content->prefix is appended to buf (if it actually fits) whereupon (ii) content->name is written to the buffer. However, the check for whether the content->name actually fits also uses 'len' rather than the updated buffer length strlen(buf). This allows us to write about "size" many bytes beyond the allocated memory. This vulnerability causes programs that use libxml2, such as PHP, to crash.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

3.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2017-05-18 06:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-14 07:16 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 3.2% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-05-18 06:29 UTC

Last modified

2026-10-14 07:16 UTC

Exploit probability

3.2% · EPSS, next 30 days

Weakness

CWE-119 · Buffer errors

Record status

Modified

Affected

• Xmlsoft libxml2 2.9.4

Attack profile CVSS 3.0 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2017-9047.md and follow it. Check whether this project is affected by CVE-2017-9047. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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