CVE-2021-34798
HighMalformed requests may cause the server to dereference a NULL pointer.
Published Mar 1, 2022 · Updated Oct 16, 2026 · Also known as ALPINE-CVE-2021-34798, BIT-apache-2021-34798, DEBIAN-CVE-2021-34798, DLA-2776-1, DSA-4982-1, SUSE-SU-2021:3299-1, SUSE-SU-2021:3522-1, TR-21-0752, TR-21-0796, TR-21-0952, UBUNTU-CVE-2021-34798, USN-5090-2
Key Facts
Patch immediately- CVE-2021-34798 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting HTTP Server (Apache), Cloud Backup (Netapp), Clustered Data Ontap (Netapp) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 65% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.49, apache 2.4.49-1, HTTP Server <=2.4.48.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
65%
Higher than 99.2% 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-2021-34798 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Malformed requests may cause the server to dereference a NULL pointer. This issue affects Apache HTTP Server 2.4.48 and earlier.
Affected Products
337 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | 12.2.1.3.0, 12.2.1.4.0, >= Apache HTTP Server 2.4 | 2.4.48 |
| Cloud BackupNetapp | See advisory | n/a |
| Clustered Data OntapNetapp | See advisory | n/a |
| StoragegridNetapp | See advisory | n/a |
| Communications Cloud Native Core Network Function Cloud Native EnvironmentOracle | 1.10.0 | n/a |
Patched Releases
apache
2.4.49, 2.4.49-1
HTTP Server
<=2.4.48
apache2
2.4.18-2ubuntu3.17+esm2, 2.4.23-29.80.1, 2.4.25-3+deb9u11, 2.4.29-1ubuntu4.17, 2.4.33-3.55.1, 2.4.38-3+deb10u6, 2.4.41-4ubuntu3.5, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1, 2.4.49-1, 2.4.49-r0, 2.4.51-1~deb11u1, 2.4.7-1ubuntu4.22+esm2
apache2-devel
2.4.23-29.80.1, 2.4.33-3.55.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-doc
2.4.23-29.80.1, 2.4.33-3.55.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-event
2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-example-pages
2.4.23-29.80.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-prefork
2.4.23-29.80.1, 2.4.33-3.55.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-utils
2.4.23-29.80.1, 2.4.33-3.55.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
apache2-worker
2.4.23-29.80.1, 2.4.33-3.55.1, 2.4.43-3.32.1, 2.4.43-lp152.2.21.1
httpd
0:2.4.6-97.el7_9.4, 2.4.37-43.0.2.module+el8.5.0+20470+f38d0c8f, 2.4.37-43.0.2.module+el8.5.0+20518+d9453e37.2, 2.4.37-43.module_el8.5.0+2630+51c6d843.2.alma, 2.4.37-43.module+el8.5.0+714+5ec56ee8, 2.4.48-3.ph1, 2.4.48-3.ph2, 2.4.48-3.ph3, 2.4.49-1, 2.4.51-1.amzn2, 2.4.52-1, 2.4.6-97.0.5.el7_9.2, 2.4.6-97.0.5.el7_9.4
httpd-devel
2.4.37-43.0.2.module+el8.5.0+20470+f38d0c8f, 2.4.37-43.0.2.module+el8.5.0+20518+d9453e37.2, 2.4.51-1.amzn2, 2.4.6-97.0.5.el7_9.2, 2.4.6-97.0.5.el7_9.4
httpd-filesystem
2.4.37-43.0.2.module+el8.5.0+20470+f38d0c8f, 2.4.37-43.0.2.module+el8.5.0+20518+d9453e37.2, 2.4.51-1.amzn2
httpd-manual
2.4.37-43.0.2.module+el8.5.0+20470+f38d0c8f, 2.4.37-43.0.2.module+el8.5.0+20518+d9453e37.2, 2.4.51-1.amzn2, 2.4.6-97.0.5.el7_9.2, 2.4.6-97.0.5.el7_9.4
httpd-tools
2.4.37-43.0.2.module+el8.5.0+20470+f38d0c8f, 2.4.37-43.0.2.module+el8.5.0+20518+d9453e37.2, 2.4.51-1.amzn2, 2.4.6-97.0.5.el7_9.2, 2.4.6-97.0.5.el7_9.4
httpd:2.4
8050020220228164203.c5368500
httpd24
2.4.51-1.94.amzn1
httpd24-devel
2.4.51-1.94.amzn1
httpd24-httpd
0:2.4.34-23.el7.5
httpd24-manual
2.4.51-1.94.amzn1
httpd24-tools
2.4.51-1.94.amzn1
jbcs-httpd24-apr
0:1.6.3-107.el8jbcs, 0:1.6.3-107.jbcs.el7
jbcs-httpd24-apr-util
0:1.6.1-84.el8jbcs, 0:1.6.1-84.jbcs.el7
jbcs-httpd24-curl
0:7.78.0-2.el8jbcs, 0:7.78.0-2.jbcs.el7
jbcs-httpd24-httpd
0:2.4.37-78.el8jbcs, 0:2.4.37-78.jbcs.el7
Timeline
Publicly disclosed
Mar 1, 2022
Last updated
Oct 16, 2026
Weakness Type
- CWE-476 NULL Pointer Dereference
References
- advisoryhttp://access.redhat.com/errata/RHSA-2022:0158
- advisoryhttp://access.redhat.com/errata/RHSA-2022:0162
- advisoryhttp://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-2332
- advisoryhttp://httpd.apache.org/security/vulnerabilities_24.html
- advisoryRHSA-2021:4613
FAQ
Common Questions.
Malformed requests may cause the server to dereference a NULL pointer.
Affected: HTTP Server (Apache) versions 12.2.1.3.0, 12.2.1.4.0, >= Apache HTTP Server 2.4; Cloud Backup (Netapp); Clustered Data Ontap (Netapp), 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 2.4.49, apache 2.4.49-1, HTTP Server <=2.4.48.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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