The dav_xml_get_cdata function in main/util.c in the mod_dav module in the Apache HTTP Server before 2.4.8 does not properly remove whitespace characters from CDATA sections, which allows remote attackers to cause a denial of service (daemon crash) via a crafted DAV WRITE request.
Conclusion & alert: CVE-2013-6438 is rated Moderate Risk (49.2/100): CVSS Medium severity, with high exploitation likelihood (EPSS 26.83%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
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 | 39.56% | 26.83% | -12.73% |
| 2 | 2026-05-08 | 30.25% | 39.56% | +9.31% |
| 3 | 2026-03-04 | — | 30.25% | — |
Full EPSS history (42 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2013-6438 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2013-6438 |
gentoo
|
high | CVE-2013-6438: 1 GLSA(s) (201408-12), 1 atom(s) (www-servers/apache); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-6438 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2013-6438 |
suse
|
medium | CVE-2013-6438 severity moderate: SUSE including 106 source package names (apache2, apache2-2.2.12-1.46.1, …), 235 product×package rows across 43 product lines (HPE Helion OpenStack 8, SUSE Linux Enterprise High Performance Computing 12 SP5, … (43 product lines)): Fixed 148, Known Not Affected 87. | https://www.suse.com/security/cve/CVE-2013-6438/ |
ubuntu
|
medium | CVE-2013-6438 medium priority: Ubuntu including 1 source packages (apache2), 5 status rows across 5 suites (lucid, precise, quantal, saucy, upstream): released 5. | https://ubuntu.com/security/CVE-2013-6438 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| apache | http_server | >= 2.2.0, < 2.2.27 | cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* |
| apache | http_server | >= 2.4.1, < 2.4.9 | cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* |
| oracle | http_server | 10.1.3.5.0 | cpe:2.3:a:oracle:http_server:10.1.3.5.0:*:*:*:*:*:*:* |
| oracle | http_server | 11.1.1.7.0 | cpe:2.3:a:oracle:http_server:11.1.1.7.0:*:*:*:*:*:*:* |
| oracle | http_server | 12.1.2.0 | cpe:2.3:a:oracle:http_server:12.1.2.0:*:*:*:*:*:*:* |
| oracle | http_server | 12.1.3.0 | cpe:2.3:a:oracle:http_server:12.1.3.0:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 10.04 | cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:* |
| canonical | ubuntu_linux | 12.04 | cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:* |
| canonical | ubuntu_linux | 12.10 | cpe:2.3:o:canonical:ubuntu_linux:12.10:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 13.10 | cpe:2.3:o:canonical:ubuntu_linux:13.10:*:*:*:*:*:*:* |