CVE-2020-1927
MediumIn 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 Apr 21, 2021 · Updated Sep 8, 2026 · Also known as ALPINE-CVE-2020-1927, BIT-apache-2020-1927, DEBIAN-CVE-2020-1927, DLA-2706-1, SUSE-SU-2020:1111-1, SUSE-SU-2020:1126-1, SUSE-SU-2020:1272-1, UBUNTU-CVE-2020-1927
Key Facts
Patch immediately- CVE-2020-1927 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting HTTP Server (Apache), Oncommand Unified Manager Core Package (Netapp), Communications Element Manager (Oracle) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 57% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.42, apache 2.4.43-1, HTTP Server <=2.4.41.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
57%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2020-1927 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Affected Products
293 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | >= 2.4.0 to 2.4.41 | 2.4.41 |
| Oncommand Unified Manager Core PackageNetapp | See advisory | n/a |
| Communications Element ManagerOracle | 8.1.1, 8.2.0, 8.2.1 | n/a |
| Communications Session Report ManagerOracle | 8.1.1, 8.2.0, 8.2.1 | n/a |
| Communications Session Route ManagerOracle | 8.1.1, 8.2.0, 8.2.1 | n/a |
Patched Releases
apache
2.4.42, 2.4.43-1
HTTP Server
<=2.4.41
apache2
2.4.16-20.29.1, 2.4.18-2ubuntu3.17, 2.4.23-29.54.1, 2.4.25-3+deb9u10, 2.4.29-1ubuntu4.14, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1, 2.4.38-3+deb10u4, 2.4.38-3+deb10u9, 2.4.41-4ubuntu3.1, 2.4.43-1, 2.4.43-r0
apache2-devel
2.4.23-29.54.1, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1
apache2-doc
2.4.16-20.29.1, 2.4.23-29.54.1, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1
apache2-event
2.4.33-lp151.8.12.1
apache2-example-pages
2.4.16-20.29.1, 2.4.23-29.54.1, 2.4.33-lp151.8.12.1
apache2-prefork
2.4.16-20.29.1, 2.4.23-29.54.1, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1
apache2-utils
2.4.16-20.29.1, 2.4.23-29.54.1, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1
apache2-worker
2.4.16-20.29.1, 2.4.23-29.54.1, 2.4.33-3.30.1, 2.4.33-lp151.8.12.1
httpd
0:2.4.6-95.el7, 2.4.37-30.0.1.module+el8.3.0+7816+49791cfd, 2.4.43-1.amzn2, 2.4.43-1.ph1, 2.4.43-1.ph2, 2.4.43-1.ph3, 2.4.6-95.0.1.el7
httpd-devel
2.4.37-30.0.1.module+el8.3.0+7816+49791cfd, 2.4.43-1.amzn2, 2.4.6-95.0.1.el7
httpd-filesystem
2.4.37-30.0.1.module+el8.3.0+7816+49791cfd, 2.4.43-1.amzn2
httpd-manual
2.4.37-30.0.1.module+el8.3.0+7816+49791cfd, 2.4.43-1.amzn2, 2.4.6-95.0.1.el7
httpd-tools
2.4.37-30.0.1.module+el8.3.0+7816+49791cfd, 2.4.43-1.amzn2, 2.4.6-95.0.1.el7
httpd:2.4
8030020200818000036.30b713e6
httpd24
2.4.43-1.89.amzn1
httpd24-devel
2.4.43-1.89.amzn1
httpd24-httpd
0:2.4.34-18.el6, 0:2.4.34-18.el7
httpd24-manual
2.4.43-1.89.amzn1
httpd24-mod_md
1:2.0.8-1.el7
httpd24-tools
2.4.43-1.89.amzn1
jbcs-httpd24-apr
0:1.6.3-86.jbcs.el6, 0:1.6.3-86.jbcs.el7
jbcs-httpd24-brotli
0:1.0.6-21.jbcs.el6, 0:1.0.6-21.jbcs.el7
jbcs-httpd24-httpd
0:2.4.37-52.jbcs.el6, 0:2.4.37-52.jbcs.el7
Timeline
Publicly disclosed
Apr 21, 2021
Last updated
Sep 8, 2026
Weakness Type
- CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
References
- advisoryopenSUSE-SU-2020:0597
- advisoryRHSA-2020:1336
- advisoryRHSA-2020:1337
- advisoryRHSA-2020:2263
- advisoryRHSA-2020:3958
FAQ
Common Questions.
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.
Affected: HTTP Server (Apache) versions >= 2.4.0 to 2.4.41; Oncommand Unified Manager Core Package (Netapp); Communications Element Manager (Oracle) versions 8.1.1, 8.2.0, 8.2.1, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including apache 2.4.42, apache 2.4.43-1, HTTP Server <=2.4.41.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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