CVE-2017-9047

Exp

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.

Published: 2017-05-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-9047 is rated High Exploit Risk (75.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.19%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2017-9047

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2017-9047

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.66% 3.19% +0.53%
2 2026-04-09 2.89% 2.66% -0.23%
3 2026-04-02 — 2.89% —

Full EPSS history (56 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-9047

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2017-9047

OS Trackers for CVE-2017-9047

vendor priority summary link
debian not yet assigned CVE-2017-9047 not yet assigned priority: Debian including 1 source packages (libxml2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-9047
gentoo normal CVE-2017-9047: 1 GLSA(s) (201711-01), 1 atom(s) (dev-libs/libxml2); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-9047
redhat medium — https://access.redhat.com/security/cve/CVE-2017-9047
suse medium CVE-2017-9047 severity moderate: SUSE including 364 source package names (0.9.1:libxml2-2-2.9.4-39.2, 1.0.0:libxml2-2-2.9.4-39.2, …), 513 product×package rows across 102 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (102 product lines)): Fixed 310, Known Affected 157, Known Not Affected 46. https://www.suse.com/security/cve/CVE-2017-9047/
ubuntu medium CVE-2017-9047 medium priority: Ubuntu including 1 source packages (libxml2), 5 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): released 4, ignored 1. https://ubuntu.com/security/CVE-2017-9047

Affected software / configurations for CVE-2017-9047

Vendor Product Version Raw CPE
xmlsoft libxml2 2.9.4 cpe:2.3:a:xmlsoft:libxml2:2.9.4:*:*:*:*:*:*:*

References for CVE-2017-9047

cvelogic Threat Intelligence