cbcvebase.
CVE-2019-0190
published 2019-01-30

CVE-2019-0190: A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a…

PriorityP277high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
ITWVulnCheck KEV
Exploited in the wild
EPSS
59.94%
99.0th percentile
A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server version 2.4.37 when using OpenSSL version 1.1.1 or later, due to an interaction in changes to handling of renegotiation attempts.

Affected

12 ranges
VendorProductVersion rangeFixed in
apachehttp_server
apachehttpd
apache_software_foundationapache_http_server
debianapache2< apache2 2.4.38-1 (bookworm)apache2 2.4.38-1 (bookworm)
oracleenterprise_manager_ops_center
oraclehospitality_guest_access
oraclehospitality_guest_access
oracleinstantis_enterprisetrack
oracleinstantis_enterprisetrack
oracleinstantis_enterprisetrack
oracleretail_xstore_point_of_service
oracleretail_xstore_point_of_service

Detection & IOCsextracted from sources · hover to see the quote

  • Target: Apache HTTP Server 2.4.37 combined with OpenSSL 1.1.1 or later — the infinite loop DoS via mod_ssl client renegotiation is only triggerable on this exact version combination
  • Attack vector: client-initiated TLS renegotiation over HTTPS — monitor for abnormal or repeated TLS renegotiation handshakes from a single remote client against mod_ssl endpoints
  • Detection signal: Apache httpd worker/process entering an infinite loop (CPU spin, unresponsive worker) following a client-initiated renegotiation — correlate with process-level monitoring of httpd workers
  • Protocol scope: exploit is delivered exclusively over HTTPS — focus TLS inspection and anomaly detection on port 443 (or any SSL/TLS-enabled listener) on Apache 2.4.37 hosts
  • ·Vulnerability is version-locked: only Apache HTTP Server 2.4.37 is affected; all earlier and later versions (including the fixed 2.4.38) are not vulnerable — version fingerprinting is essential before triaging alerts
  • ·OpenSSL version is a hard prerequisite: the bug only manifests when OpenSSL 1.1.1 or later is in use; systems running older OpenSSL with Apache 2.4.37 are not exploitable
  • ·All Red Hat Enterprise Linux (5–8), JBoss, and Red Hat Software Collections packages are listed as Not Affected — do not prioritize patching effort on RHEL-based deployments of httpd
  • ·Fix is available in Apache 2.4.38; Debian resolved the issue in package version 2.4.38-1 across all tracked suites

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
osv7.5HIGH
vulncheck7.5HIGH
vendor_apache7.5HIGH
vendor_debian7.5HIGH
vendor_oracle7.5HIGH
vendor_redhat7.5HIGH
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