cbcvebase.
CVE-2023-5043
published 2023-10-25

CVE-2023-5043: Ingress nginx annotation injection causes arbitrary command execution.

PriorityP259high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
2.23%
80.6th percentile
Ingress nginx annotation injection causes arbitrary command execution.

Affected

2 ranges
VendorProductVersion rangeFixed in
k8s.ioingress-nginx>= 0 < 1.9.01.9.0
kubernetesingress-nginx< 1.9.01.9.0

Detection & IOCsextracted from sources · hover to see the quote

urlgithub.com/r0binak/CVE-2023-5043
snort
alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET WEB_SERVER Kubernetes Ingress NGINX Controller configuration-snippet Annotation Injection (CVE-2023-5044)"; flow:established,to_server; http.method; content:"POST"; http.content_type; content:"application/json"; http.request_body; content:"|22|admission.k8s.io/v1|22 2c|"; content:"|22|nginx.ingress.kubernetes.io/configuration-snippet|22 3a|"; fast_pattern; pcre:"/^\s*?\x22[^\x2c]*?(?:content_by_lua|\x23|\x3b\x7d)/R"; reference:url,github.com/r0binak/CVE-2023-5043; reference:cve,2023-5044; classtype:web-application-attack; sid:2061121; rev:1; metadata:affected_product Kubernetes, attack_target Server, tls_state TLSDecrypt, created_at 2025_03_27, cve CVE_2023_5044, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2025_03_27, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)
  • The injected annotation value contains NGINX Lua execution directives (content_by_lua), comment characters (#), or block-termination sequences (;}) — match these patterns immediately after the annotation key in the JSON body.
  • Requests include the Kubernetes admission API version string 'admission.k8s.io/v1' in the JSON body, which can serve as a pre-filter before checking for the malicious annotation.
  • Detection should be applied at the perimeter and internally, and requires TLS decryption (TLSDecrypt) to inspect the payload in encrypted environments.
  • ·The Snort/Suricata rule (sid:2061121) references CVE-2023-5044 in its metadata and rule message, but is cross-referenced to CVE-2023-5043 via the GitHub PoC URL — confirm the correct CVE scope before deploying to avoid alert mislabeling.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
ghsa8.8HIGH
osv8.8HIGH
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