CVE-2017-9047
Description
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.
How to fix CVE-2017-9047
To remediate CVE-2017-9047, upgrade the affected package to a fixed version below.
- —upgrade to 2.9.4+dfsg1-3.1 or later
Is CVE-2017-9047 being exploited?
Low — EPSS is 2.7%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2.9.4+dfsg1-3.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |