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.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-1008-1 libxml2 security update
Debian DLA Debian DLA DLA-4064-1 libxml2 security update
Debian DSA Debian DSA DSA-3952-1 libxml2 security update
EUVD EUVD EUVD-2017-17987 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.
Ubuntu USN Ubuntu USN USN-3424-1 libxml2 vulnerabilities
Ubuntu USN Ubuntu USN USN-3424-2 libxml2 vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.01286}

epss

{'score': 0.014}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2024-08-05T16:55:21.859Z

Reserved: 2017-05-18T00:00:00

Link: CVE-2017-9047

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2017-05-18T06:29:00.403

Modified: 2025-04-20T01:37:25.860

Link: CVE-2017-9047

cve-icon Redhat

Severity : Moderate

Publid Date: 2017-05-15T00:00:00Z

Links: CVE-2017-9047 - Bugzilla

cve-icon OpenCVE Enrichment

No data.