CVE-2020-1927

In Apache HTTP Server 2.4.0 to 2.4.41, redirects configured with mod_rewrite that were intended to be self-referential might be fooled by encoded newlines and redirect instead to an an unexpected URL within the request URL.

Published: 2020-04-01 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-1927 is rated Moderate Risk (57.3/100): CVSS Medium severity, with high exploitation likelihood (EPSS 56.69%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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-2020-1927

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 2026-06-20 58.39% 56.69% -1.70%
2 2026-06-19 61.18% 58.39% -2.79%
3 2026-06-15 — 61.18% —

Full EPSS history (55 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-1927

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2020-1927

OS Trackers for CVE-2020-1927

vendor priority summary link
alpine medium CVE-2020-1927: 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-2020-1927
debian low CVE-2020-1927 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-2020-1927
redhat medium — https://access.redhat.com/security/cve/CVE-2020-1927
ubuntu low CVE-2020-1927 low priority: Ubuntu including 1 source packages (apache2), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 11, released 4, ignored 1, needed 1. https://ubuntu.com/security/CVE-2020-1927

Affected software / configurations for CVE-2020-1927

Vendor Product Version Raw CPE
apache http_server >= 2.4.0, <= 2.4.41 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
netapp oncommand_unified_manager_core_package — cpe:2.3:a:netapp:oncommand_unified_manager_core_package:-:*:*:*:*:*:*:*
broadcom brocade_fabric_operating_system — cpe:2.3:o:broadcom:brocade_fabric_operating_system:-:*:*:*:*:*:*:*
oracle communications_element_manager 8.1.1 cpe:2.3:a:oracle:communications_element_manager:8.1.1:*:*:*:*:*:*:*
oracle communications_element_manager 8.2.0 cpe:2.3:a:oracle:communications_element_manager:8.2.0:*:*:*:*:*:*:*
oracle communications_element_manager 8.2.1 cpe:2.3:a:oracle:communications_element_manager:8.2.1:*:*:*:*:*:*:*
oracle communications_session_report_manager 8.1.1 cpe:2.3:a:oracle:communications_session_report_manager:8.1.1:*:*:*:*:*:*:*
oracle communications_session_report_manager 8.2.0 cpe:2.3:a:oracle:communications_session_report_manager:8.2.0:*:*:*:*:*:*:*
oracle communications_session_report_manager 8.2.1 cpe:2.3:a:oracle:communications_session_report_manager:8.2.1:*:*:*:*:*:*:*
oracle communications_session_route_manager 8.1.1 cpe:2.3:a:oracle:communications_session_route_manager:8.1.1:*:*:*:*:*:*:*
oracle communications_session_route_manager 8.2.0 cpe:2.3:a:oracle:communications_session_route_manager:8.2.0:*:*:*:*:*:*:*
oracle communications_session_route_manager 8.2.1 cpe:2.3:a:oracle:communications_session_route_manager:8.2.1:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.4.0.0 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*
oracle instantis_enterprisetrack >= 17.1, <= 17.3 cpe:2.3:a:oracle:instantis_enterprisetrack:*:*:*:*:*:*:*:*
oracle sd-wan_aware 8.2 cpe:2.3:a:oracle:sd-wan_aware:8.2:*:*:*:*:*:*:*
oracle zfs_storage_appliance_kit 8.8 cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*

References for CVE-2020-1927

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00002.html Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/04/03/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/04/04/1 Mailing List Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r09bb998baee74a2c316446bd1a41ae7f8d7049d09d9ff991471e8775%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r10b853ea87dd150b0e76fda3f8254dfdb23dd05fa55596405b58478e%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r1719675306dfbeaceff3dc63ccad3de2d5615919ca3c13276948b9ac%40%3Cdev.httpd.apache.org%3E
https://lists.apache.org/thread.html/r3c5c3104813c1c5508b55564b66546933079250a46ce50eee90b2e36%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r52a52fd60a258f5999a8fa5424b30d9fd795885f9ff4828d889cd201%40%3Cdev.httpd.apache.org%3E
https://lists.apache.org/thread.html/r6a4146bf3d1645af2880f8b7a4fd8afd696d5fd4a3ae272f49f5dc84%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r70ba652b79ba224b2cbc0a183078b3a49df783b419903e3dcf4d78c7%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r731d43caece41d78d8c6304641a02a369fd78300e7ffaf566b06bc59%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/rdf3e5d0a5f5c3d90d6013bccc6c4d5af59cf1f8c8dea5d9a283d13ce%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/2021/07/msg00006.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A2RN46PRBJE7E7OPD4YZX5SVWV5QKGV5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HYVYE2ZERFXDV6RMKK3I5SDSDQLPSEIQ/
https://security.netapp.com/advisory/ntap-20200413-0002/ Third Party Advisory
https://usn.ubuntu.com/4458-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4757 Third Party Advisory
https://www.oracle.com/security-alerts/cpuApr2021.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2020.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html
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