VulnerabilityAnalyzed
CVE-2021-33193
A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning.
HIGH 7.5EPSS 46.2%
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 46.2%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 46.18% probability · 99th percentile
- CISA KEV
- Not listed
- Affected
- debian/debian linux · apache/http server · fedoraproject/fedora · tenable/tenable.sc · oracle/secure backup · oracle/zfs storage appliance kit
- Source
- security@apache.org
References
- https://github.com/apache/httpd/commit/ecebcc035ccd8d0e2984fe41420d9e944f456b3c.patchPatch
- https://lists.apache.org/thread.html/re4162adc051c1a0a79e7a24093f3776373e8733abaff57253fef341d%40%3Ccvs.httpd.apache.org%3EPatch
- https://lists.apache.org/thread.html/ree7519d71415ecdd170ff1889cab552d71758d2ba2904a17ded21a70%40%3Ccvs.httpd.apache.org%3EPatch
- https://lists.debian.org/debian-lts-announce/2023/03/msg00002.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/Third Party Advisory
- https://portswigger.net/research/http2Exploit, Third Party Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210917-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQThird 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
- https://github.com/apache/httpd/commit/ecebcc035ccd8d0e2984fe41420d9e944f456b3c.patchPatch
- https://lists.apache.org/thread.html/re4162adc051c1a0a79e7a24093f3776373e8733abaff57253fef341d%40%3Ccvs.httpd.apache.org%3EPatch
- https://lists.apache.org/thread.html/ree7519d71415ecdd170ff1889cab552d71758d2ba2904a17ded21a70%40%3Ccvs.httpd.apache.org%3EPatch
- https://lists.debian.org/debian-lts-announce/2023/03/msg00002.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/Third Party Advisory
- https://portswigger.net/research/http2Exploit, Third Party Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210917-0004/Third Party Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQThird 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.