VulnerabilityModified
CVE-2021-34798
Malformed requests may cause the server to dereference a NULL pointer.
HIGH 7.5EPSS 64.5%
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 64.5%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
Malformed requests may cause the server to dereference a NULL pointer. This issue affects Apache HTTP Server 2.4.48 and earlier.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 64.51% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- apache/http server · fedoraproject/fedora · debian/debian linux · netapp/cloud backup · netapp/clustered data ontap · netapp/storagegrid · tenable/tenable.sc · oracle/communications cloud native core network function cloud native environment · oracle/enterprise manager base platform · oracle/http server · oracle/instantis enterprisetrack · oracle/peoplesoft enterprise peopletools · oracle/zfs storage appliance kit · broadcom/brocade fabric operating system firmware · siemens/ruggedcom nms · siemens/sinec nms · siemens/sinema remote connect server · siemens/sinema server
- Source
- security@apache.org
EPSS 64.5% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdfPatch, Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10379Third Party Advisory
- https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211008-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQThird Party Advisory
- https://www.debian.org/security/2021/dsa-4982Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.tenable.com/security/tns-2021-17Third Party Advisory
- http://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdfPatch, Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10379Third Party Advisory
- https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/10/msg00001.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211008-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.