CVE-2017-9788

In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initialized or reset before or between successive key=value assignments by mod_auth_digest. Providing an initial key with no '=' assignment could reflect the stale value of uninitialized pool memory used by the prior request, leading to leakage of potentially confidential information, and a segfault in other cases resulting in denial of service.

Published: 2017-07-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-9788 is rated High Risk (76/100): CVSS Critical severity, with high exploitation likelihood (EPSS 56.77%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +7.27% over the last day, indicating growing attacker interest. 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.

Exploit prediction scoring system (EPSS) score for CVE-2017-9788

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 49.50% 56.77% +7.27%
2 2026-05-10 47.06% 49.50% +2.43%
3 2026-04-27 — 47.06% —

Full EPSS history (69 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-9788

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:H)
Serious risk that confidential data gets exposed in a big 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 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2017-9788

OS Trackers for CVE-2017-9788

vendor priority summary link
debian not yet assigned CVE-2017-9788 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-2017-9788
gentoo normal CVE-2017-9788: 1 GLSA(s) (201710-32), 1 atom(s) (www-servers/apache); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-9788
redhat high — https://access.redhat.com/security/cve/CVE-2017-9788
suse medium CVE-2017-9788 severity moderate: SUSE including 48 source package names (apache2, apache2-2.2.34-70.5.1, …), 123 product×package rows across 25 product lines (SUSE Liberty Linux 7, SUSE Linux Enterprise High Performance Computing 12 SP5, … (25 product lines)): Fixed 122, Known Not Affected 1. https://www.suse.com/security/cve/CVE-2017-9788/
ubuntu medium CVE-2017-9788 medium priority: Ubuntu including 1 source packages (apache2), 5 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): released 4, ignored 1. https://ubuntu.com/security/CVE-2017-9788

Affected software / configurations for CVE-2017-9788

Vendor Product Version Raw CPE
apache http_server <= 2.2.33 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
apache http_server >= 2.4.0, <= 2.4.26 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
apple mac_os_x < 10.13.1 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
netapp oncommand_unified_manager — cpe:2.3:a:netapp:oncommand_unified_manager:-:*:*:*:*:7-mode:*:*
netapp storage_automation_store — cpe:2.3:a:netapp:storage_automation_store:-:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 6.7 cpe:2.3:o:redhat:enterprise_linux_server_eus:6.7:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.5 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
redhat jboss_core_services 1.0 cpe:2.3:a:redhat:jboss_core_services:1.0:*:*:*:*:*:*:*
redhat jboss_enterprise_application_platform 6.0.0 cpe:2.3:a:redhat:jboss_enterprise_application_platform:6.0.0:*:*:*:*:*:*:*
redhat jboss_enterprise_application_platform 6.4.0 cpe:2.3:a:redhat:jboss_enterprise_application_platform:6.4.0:*:*:*:*:*:*:*
redhat jboss_enterprise_web_server 2.0.0 cpe:2.3:a:redhat:jboss_enterprise_web_server:2.0.0:*:*:*:*:*:*:*
oracle secure_global_desktop 5.3 cpe:2.3:a:oracle:secure_global_desktop:5.3:*:*:*:*:*:*:*

References for CVE-2017-9788

URL Tags
http://www.debian.org/security/2017/dsa-3913 Third Party Advisory
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html Patch Third Party Advisory
http://www.securityfocus.com/bid/99569 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1038906 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2017:2478 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2479 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2483 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2708 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2709 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:2710 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3113 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3114 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3193 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3194 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3195 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3239 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:3240 Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_22.html Vendor Advisory
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
https://lists.apache.org/thread.html/0dd69204a6bd643cc4e9ccd008f07a9375525d977c6ebeb07a881afb%40%3Cannounce.httpd.apache.org%3E
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r15f9aa4427581a1aecb4063f1b4b983511ae1c9935e2a0a6876dad3c%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r6521a7f62276340eabdb3339b2aa9a38c5f59d978497a1f794af53be%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r8c9983f1172a3415f915ddb7e14de632d2d0c326eb1285755a024165%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r9ea3538f229874c80a10af473856a81fbf5f694cd7f471cc679ba70b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rad01d817195e6cc871cb1d73b207ca326379a20a6e7f30febaf56d24%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rdca61ae990660bacb682295f2a09d34612b7bb5f457577fe17f4d064%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rfcf929bd33a6833e3f0c35eebdad70d5060665f9c4e17ea467c66770%40%3Ccvs.httpd.apache.org%3E
https://security.gentoo.org/glsa/201710-32 Third Party Advisory
https://security.netapp.com/advisory/ntap-20170911-0002/ Third Party Advisory
https://support.apple.com/HT208221 Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03908en_us Third Party Advisory
https://www.tenable.com/security/tns-2019-09
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