Servers and applications
CVE-2017-9047
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)…
- Severity
- High 7.5
- Published
- 18 May 2017
- Last changed
- 14 Oct 2026
- Added to UpHeron
- 1 Nov 2026
- Exploit chance
- 3.2% in the next 30 daysHigher than 88% of CVEs. EPSS by FIRST, 11 Nov 2026
- Weakness
- Memory buffer errors (CWE-119)
- Attack
- Over the network · No login needed · No user action needed
- Attacker can
- Take it down
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Sources
- NVD
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.
Affected software
| Software | Affected versions |
|---|---|
libxml2Servers and applications · cpe:a:xmlsoft:libxml2 |
|