CVE-2018-17199

In Apache HTTP Server 2.4 release 2.4.37 and prior, mod_session checks the session expiry time before decoding the session. This causes session expiry time to be ignored for mod_session_cookie sessions since the expiry time is loaded when the session is decoded.

Published: 2019-01-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-17199 is rated High Risk (69/100): CVSS High severity, with high exploitation likelihood (EPSS 19.99%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +9.54% 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-2018-17199

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 10.46% 19.99% +9.54%
2 2026-05-26 10.42% 10.46% +0.04%
3 2026-04-29 — 10.42% —

Full EPSS history (48 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-17199

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:H/A:N 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N 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:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-17199

OS Trackers for CVE-2018-17199

vendor priority summary link
alpine high CVE-2018-17199: 1 source package rows (apache2); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2018-17199
debian low CVE-2018-17199 low 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-2018-17199
gentoo normal CVE-2018-17199: 1 GLSA(s) (201903-21), 1 atom(s) (www-servers/apache); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-17199
redhat medium — https://access.redhat.com/security/cve/CVE-2018-17199
suse medium CVE-2018-17199 severity moderate: SUSE including 67 source package names (apache2, apache2-2.4.10-14.36.1, …), 129 product×package rows across 27 product lines (SLES for SAP Applications 11 SP3, SUSE Liberty Linux 7, … (27 product lines)): Fixed 110, Known Not Affected 19. https://www.suse.com/security/cve/CVE-2018-17199/
ubuntu low CVE-2018-17199 low priority: Ubuntu including 1 source packages (apache2), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 5. https://ubuntu.com/security/CVE-2018-17199

Affected software / configurations for CVE-2018-17199

Vendor Product Version Raw CPE
apache http_server >= 2.4.0, <= 2.4.37 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:*:*:*:*:*:*:*
netapp santricity_cloud_connector — cpe:2.3:a:netapp:santricity_cloud_connector:-:*:*:*:*:*:*:*
netapp storage_automation_store — cpe:2.3:a:netapp:storage_automation_store:-:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.3.3 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.3.3:*:*:*:*:*:*:*

References for CVE-2018-17199

URL Tags
http://www.securityfocus.com/bid/106742 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2019:3932
https://access.redhat.com/errata/RHSA-2019:3933
https://access.redhat.com/errata/RHSA-2019:3935
https://access.redhat.com/errata/RHSA-2019:4126
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
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/r03ee478b3dda3e381fd6189366fa7af97c980d2f602846eef935277d%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%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/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%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/rd2fb621142e7fa187cfe12d7137bf66e7234abcbbcd800074c84a538%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/re473305a65b4db888e3556e4dae10c2a04ee89dcff2e26ecdbd860a9%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E
https://lists.debian.org/debian-lts-announce/2019/01/msg00024.html Mailing List Third Party Advisory
https://seclists.org/bugtraq/2019/Apr/5 Issue Tracking Mailing List Third Party Advisory
https://security.gentoo.org/glsa/201903-21 Third Party Advisory
https://security.netapp.com/advisory/ntap-20190125-0001/ Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03950en_us
https://usn.ubuntu.com/3937-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4422 Third Party Advisory
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html Patch Third Party Advisory
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
https://www.tenable.com/security/tns-2019-09
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