CVE-2023-44487

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as...

Basic Information

CVE State
PUBLISHED
Reserved Date
September 29, 2023
Published Date
October 10, 2023
Last Updated
June 07, 2025
Vendor
n/a
Product
n/a
Description
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
Tags
cisa nessus_scanner

CVSS Scores

CVSS v3.1

7.5 - HIGH

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC Information

Exploitation
active
Automatable
Yes
Technical Impact
partial

Exploit Status

Exploited in the Wild
Yes (2023-10-10 00:00:00 UTC) Source
Proof of Concept Available
Yes (added 2023-12-11 23:12:03 UTC) Source

References

https://github.com/dotnet/core/blob/e4613450ea0da7fd2fc6b61dfb2c1c1dec1ce9ec/release-notes/6.0/6.0.23/6.0.23.md?plain=1#L73 https://blog.cloudflare.com/technical-breakdown-http2-rapid-reset-ddos-attack/ https://aws.amazon.com/security/security-bulletins/AWS-2023-011/ https://cloud.google.com/blog/products/identity-security/how-it-works-the-novel-http2-rapid-reset-ddos-attack https://www.nginx.com/blog/http-2-rapid-reset-attack-impacting-f5-nginx-products/ https://cloud.google.com/blog/products/identity-security/google-cloud-mitigated-largest-ddos-attack-peaking-above-398-million-rps/ https://news.ycombinator.com/item?id=37831062 https://blog.cloudflare.com/zero-day-rapid-reset-http2-record-breaking-ddos-attack/ https://www.phoronix.com/news/HTTP2-Rapid-Reset-Attack https://github.com/envoyproxy/envoy/pull/30055 https://github.com/haproxy/haproxy/issues/2312 https://github.com/eclipse/jetty.project/issues/10679 https://forums.swift.org/t/swift-nio-http2-security-update-cve-2023-44487-http-2-dos/67764 https://github.com/nghttp2/nghttp2/pull/1961 https://github.com/netty/netty/commit/58f75f665aa81a8cbcf6ffa74820042a285c5e61 https://github.com/alibaba/tengine/issues/1872 https://github.com/apache/tomcat/tree/main/java/org/apache/coyote/http2 https://news.ycombinator.com/item?id=37830987 https://news.ycombinator.com/item?id=37830998 https://github.com/caddyserver/caddy/issues/5877 https://www.bleepingcomputer.com/news/security/new-http-2-rapid-reset-zero-day-attack-breaks-ddos-records/ https://github.com/bcdannyboy/CVE-2023-44487 https://github.com/grpc/grpc-go/pull/6703 https://github.com/icing/mod_h2/blob/0a864782af0a942aa2ad4ed960a6b32cd35bcf0a/mod_http2/README.md?plain=1#L239-L244 https://github.com/nghttp2/nghttp2/releases/tag/v1.57.0 https://mailman.nginx.org/pipermail/nginx-devel/2023-October/S36Q5HBXR7CAIMPLLPRSSSYR4PCMWILK.html https://my.f5.com/manage/s/article/K000137106 https://msrc.microsoft.com/blog/2023/10/microsoft-response-to-distributed-denial-of-service-ddos-attacks-against-http/2/ https://bugzilla.proxmox.com/show_bug.cgi?id=4988 https://cgit.freebsd.org/ports/commit/?id=c64c329c2c1752f46b73e3e6ce9f4329be6629f9 http://www.openwall.com/lists/oss-security/2023/10/10/7 http://www.openwall.com/lists/oss-security/2023/10/10/6 https://seanmonstar.com/post/730794151136935936/hyper-http2-rapid-reset-unaffected https://github.com/microsoft/CBL-Mariner/pull/6381 https://groups.google.com/g/golang-announce/c/iNNxDTCjZvo https://github.com/facebook/proxygen/pull/466 https://gist.github.com/adulau/7c2bfb8e9cdbe4b35a5e131c66a0c088 https://github.com/micrictor/http2-rst-stream https://edg.io/lp/blog/resets-leaks-ddos-and-the-tale-of-a-hidden-cve https://openssf.org/blog/2023/10/10/http-2-rapid-reset-vulnerability-highlights-need-for-rapid-response/ https://github.com/h2o/h2o/security/advisories/GHSA-2m7v-gc89-fjqf https://github.com/h2o/h2o/pull/3291 https://github.com/nodejs/node/pull/50121 https://github.com/dotnet/announcements/issues/277 https://github.com/golang/go/issues/63417 https://github.com/advisories/GHSA-vx74-f528-fxqg https://github.com/apache/trafficserver/pull/10564 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-44487 https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.14 https://lists.apache.org/thread/5py8h42mxfsn8l1wy6o41xwhsjlsd87q https://www.openwall.com/lists/oss-security/2023/10/10/6 https://www.haproxy.com/blog/haproxy-is-not-affected-by-the-http-2-rapid-reset-attack-cve-2023-44487 https://github.com/opensearch-project/data-prepper/issues/3474 https://github.com/kubernetes/kubernetes/pull/121120 https://github.com/oqtane/oqtane.framework/discussions/3367 https://github.com/advisories/GHSA-xpw8-rcwv-8f8p https://netty.io/news/2023/10/10/4-1-100-Final.html https://www.cisa.gov/news-events/alerts/2023/10/10/http2-rapid-reset-vulnerability-cve-2023-44487 https://www.theregister.com/2023/10/10/http2_rapid_reset_zeroday/ https://blog.qualys.com/vulnerabilities-threat-research/2023/10/10/cve-2023-44487-http-2-rapid-reset-attack https://news.ycombinator.com/item?id=37837043 https://github.com/kazu-yamamoto/http2/issues/93 https://martinthomson.github.io/h2-stream-limits/draft-thomson-httpbis-h2-stream-limits.html https://github.com/kazu-yamamoto/http2/commit/f61d41a502bd0f60eb24e1ce14edc7b6df6722a1 https://github.com/apache/httpd/blob/afcdbeebbff4b0c50ea26cdd16e178c0d1f24152/modules/http2/h2_mplx.c#L1101-L1113 https://www.debian.org/security/2023/dsa-5522 https://www.debian.org/security/2023/dsa-5521 https://access.redhat.com/security/cve/cve-2023-44487 https://github.com/ninenines/cowboy/issues/1615 https://github.com/varnishcache/varnish-cache/issues/3996 https://github.com/tempesta-tech/tempesta/issues/1986 https://blog.vespa.ai/cve-2023-44487/ https://github.com/etcd-io/etcd/issues/16740 https://www.darkreading.com/cloud/internet-wide-zero-day-bug-fuels-largest-ever-ddos-event https://istio.io/latest/news/security/istio-security-2023-004/ https://github.com/junkurihara/rust-rpxy/issues/97 https://bugzilla.suse.com/show_bug.cgi?id=1216123 https://bugzilla.redhat.com/show_bug.cgi?id=2242803 https://ubuntu.com/security/CVE-2023-44487 https://community.traefik.io/t/is-traefik-vulnerable-to-cve-2023-44487/20125 https://github.com/advisories/GHSA-qppj-fm5r-hxr3 https://github.com/apache/httpd-site/pull/10 https://github.com/projectcontour/contour/pull/5826 https://github.com/linkerd/website/pull/1695/commits/4b9c6836471bc8270ab48aae6fd2181bc73fd632 https://github.com/line/armeria/pull/5232 https://blog.litespeedtech.com/2023/10/11/rapid-reset-http-2-vulnerablilty/ https://security.paloaltonetworks.com/CVE-2023-44487 https://github.com/akka/akka-http/issues/4323 https://github.com/openresty/openresty/issues/930 https://github.com/apache/apisix/issues/10320 https://github.com/Azure/AKS/issues/3947 https://github.com/Kong/kong/discussions/11741 https://github.com/arkrwn/PoC/tree/main/CVE-2023-44487 https://www.netlify.com/blog/netlify-successfully-mitigates-cve-2023-44487/ https://github.com/caddyserver/caddy/releases/tag/v2.7.5 https://lists.debian.org/debian-lts-announce/2023/10/msg00020.html http://www.openwall.com/lists/oss-security/2023/10/13/4 http://www.openwall.com/lists/oss-security/2023/10/13/9 https://arstechnica.com/security/2023/10/how-ddosers-used-the-http-2-protocol-to-deliver-attacks-of-unprecedented-size/ https://lists.w3.org/Archives/Public/ietf-http-wg/2023OctDec/0025.html https://lists.fedoraproject.org/archives/list/[email protected]/message/JMEXY22BFG5Q64HQCM5CK2Q7KDKVV4TY/ https://linkerd.io/2023/10/12/linkerd-cve-2023-44487/ https://lists.debian.org/debian-lts-announce/2023/10/msg00023.html https://security.netapp.com/advisory/ntap-20231016-0001/ https://lists.debian.org/debian-lts-announce/2023/10/msg00024.html http://www.openwall.com/lists/oss-security/2023/10/18/4 http://www.openwall.com/lists/oss-security/2023/10/18/8 http://www.openwall.com/lists/oss-security/2023/10/19/6 https://lists.fedoraproject.org/archives/list/[email protected]/message/ZKQSIKIAT5TJ3WSLU3RDBQ35YX4GY4V3/ https://lists.fedoraproject.org/archives/list/[email protected]/message/JIZSEFC3YKCGABA2BZW6ZJRMDZJMB7PJ/ http://www.openwall.com/lists/oss-security/2023/10/20/8 https://lists.fedoraproject.org/archives/list/[email protected]/message/WLPRQ5TWUQQXYWBJM7ECYDAIL2YVKIUH/ https://lists.fedoraproject.org/archives/list/[email protected]/message/E72T67UPDRXHIDLO3OROR25YAMN4GGW5/ https://lists.fedoraproject.org/archives/list/[email protected]/message/BFQD3KUEMFBHPAPBGLWQC34L4OWL5HAZ/ https://lists.fedoraproject.org/archives/list/[email protected]/message/ZLU6U2R2IC2K64NDPNMV55AUAO65MAF4/ https://lists.fedoraproject.org/archives/list/[email protected]/message/X6QXN4ORIVF6XBW4WWFE7VNPVC74S45Y/ https://lists.fedoraproject.org/archives/list/[email protected]/message/LKYHSZQFDNR7RSA7LHVLLIAQMVYCUGBG/ https://lists.fedoraproject.org/archives/list/[email protected]/message/FNA62Q767CFAFHBCDKYNPBMZWB7TWYVU/ https://lists.fedoraproject.org/archives/list/[email protected]/message/LNMZJCDHGLJJLXO4OXWJMTVQRNWOC7UL/ https://lists.fedoraproject.org/archives/list/[email protected]/message/KSEGD2IWKNUO3DWY4KQGUQM5BISRWHQE/ https://lists.fedoraproject.org/archives/list/[email protected]/message/CLB4TW7KALB3EEQWNWCN7OUIWWVWWCG2/ https://lists.debian.org/debian-lts-announce/2023/10/msg00045.html https://www.debian.org/security/2023/dsa-5540 https://lists.debian.org/debian-lts-announce/2023/10/msg00047.html https://discuss.hashicorp.com/t/hcsec-2023-32-vault-consul-and-boundary-affected-by-http-2-rapid-reset-denial-of-service-vulnerability-cve-2023-44487/59715 https://lists.fedoraproject.org/archives/list/[email protected]/message/VHUHTSXLXGXS7JYKBXTA3VINUPHTNGVU/ https://lists.fedoraproject.org/archives/list/[email protected]/message/VSRDIV77HNKUSM7SJC5BKE5JSHLHU2NK/ https://lists.fedoraproject.org/archives/list/[email protected]/message/3N4NJ7FR4X4FPZUGNTQAPSTVB2HB2Y4A/ https://lists.fedoraproject.org/archives/list/[email protected]/message/ZB43REMKRQR62NJEI7I5NQ4FSXNLBKRT/ https://lists.fedoraproject.org/archives/list/[email protected]/message/HT7T2R4MQKLIF4ODV4BDLPARWFPCJ5CZ/ https://lists.fedoraproject.org/archives/list/[email protected]/message/XFOIBB4YFICHDM7IBOP7PWXW3FX4HLL2/ https://lists.debian.org/debian-lts-announce/2023/11/msg00001.html https://www.debian.org/security/2023/dsa-5549 https://lists.fedoraproject.org/archives/list/[email protected]/message/2MBEPPC36UBVOZZNAXFHKLFGSLCMN5LI/ https://lists.fedoraproject.org/archives/list/[email protected]/message/WE2I52RHNNU42PX6NZ2RBUHSFFJ2LVZX/ https://www.debian.org/security/2023/dsa-5558 https://lists.debian.org/debian-lts-announce/2023/11/msg00012.html https://security.gentoo.org/glsa/202311-09 https://www.debian.org/security/2023/dsa-5570 https://security.netapp.com/advisory/ntap-20240426-0007/ https://security.netapp.com/advisory/ntap-20240621-0006/ https://security.netapp.com/advisory/ntap-20240621-0007/ https://github.com/grpc/grpc/releases/tag/v1.59.2 https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-http2-reset-d8Kf32vZ

Known Exploited Vulnerability Information

Source Added Date
CISA 2023-10-10 00:00:00 UTC

Recent Mentions

Siemens SIMATIC S7-1500 CPU Family

Source: All CISA Advisories • Published: 2025-06-12 12:00:00 UTC

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v4 8.7 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: SIMATIC S7-1500 CPU family Vulnerabilities: Missing Encryption of Sensitive Data, Out-of-bounds Read, Use After Free, Stack-based Buffer Overflow, Incorrect Provision of Specified Functionality, Out-of-bounds Write, Incorrect Calculation of Buffer Size, Heap-based Buffer Overflow, External Control of File Name or Path, Uncontrolled Resource Consumption, Improper Input Validation, Truncation of Security-relevant Information, Missing Critical Step in Authentication, Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), Access of Resource Using Incompatible Type ('Type Confusion'), Signal Handler Race Condition, Inefficient Algorithmic Complexity, Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), NULL Pointer Dereference, Reachable Assertion, Return of Pointer Value Outside of Expected Range, Improper Handling of Length Parameter Inconsistency, Integer Overflow or Wraparound, Improper Locking, Improper Validation of Array Index, Buffer Underwrite ('Buffer Underflow'), Use of Uninitialized Resource, Detection of Error Condition Without Action, Premature Release of Resource During Expected Lifetime 2. RISK EVALUATION Successful exploitation of these vulnerabilities could allow an attacker to affect the confidentiality, integrity, or availability of affected devices. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS Siemens reports that the following products are affected: SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): V3.1.5 and...

Scanner Integrations

Scanner URL Date Detected
Nessus https://www.tenable.com/plugins/nessus/502811 2025-06-02 13:58:51 UTC

Potential Proof of Concepts

Warning: These PoCs have not been tested and could contain malware. Use at your own risk.

threatlabindonesia/CVE-2023-44487-HTTP-2-Rapid-Reset-Exploit-PoC

Type: github • Created: 2024-12-03 14:54:21 UTC • Stars: 3

sigridou/CVE-2023-44487-

Type: github • Created: 2023-12-11 23:12:03 UTC • Stars: 0

ReToCode/golang-CVE-2023-44487

Type: github • Created: 2023-10-25 09:11:46 UTC • Stars: 2

studiogangster/CVE-2023-44487

Type: github • Created: 2023-10-16 11:07:50 UTC • Stars: 19

A python based exploit to test out rapid reset attack (CVE-2023-44487)

imabee101/CVE-2023-44487

Type: github • Created: 2023-10-11 01:59:47 UTC • Stars: 54

Proof of concept for DoS exploit

bcdannyboy/CVE-2023-44487

Type: github • Created: 2023-10-10 14:20:42 UTC • Stars: 230

Basic vulnerability scanning to see if web servers may be vulnerable to CVE-2023-44487

Timeline

  • CVE ID Reserved

  • CVE Published to Public

  • Added to KEVIntel

  • Proof of Concept Exploit Available

  • Detected by Nessus