cbcvebase.
CVE-2016-4555
published 2016-05-10

CVE-2016-4555: client_side_request.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via crafted Edge Side…

PriorityP350high7.5CVSS 3.0
AVNACLPRNUINSUCNINAH
EPSS
53.92%
98.9th percentile
client_side_request.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via crafted Edge Side Includes (ESI) responses.

Affected

149 ranges· showing 25
VendorProductVersion rangeFixed in
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
debiansquid
oraclelinux
oraclelinux
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid
squid-cachesquid

Detection & IOCsextracted from sources · hover to see the quote

  • Vulnerability is triggered via crafted ESI (Edge Side Includes) responses from a remote server; monitor Squid worker process crashes (SIGSEGV/NULL pointer dereference) originating from ESI response processing in client_side_request.cc
  • Attack vector requires Squid operating as a reverse proxy or performing TLS/HTTPS interception; scope detection to those deployment modes
  • Crash originates specifically from ESIInclude::Start; look for segfault stack traces referencing this function in Squid crash logs
  • Root cause is incorrect pointer handling in ESI response processing; due to incorrect pointer handling Squid is vulnerable to a denial of service attack when processing ESI responses
  • ·Red Hat Enterprise Linux 5 and 6 stock squid packages are listed as Not Affected; only RHEL 7 and Fedora deployments required patching
  • ·Affected versions are Squid 3.x before 3.5.18 and 4.x before 4.0.10; deployments on these versions in reverse-proxy or TLS interception mode are at risk

CVSS provenance

nvdv3.07.5HIGHCVSS:3.0/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
osv8.2HIGH
vendor_ubuntu8.2HIGH
vendor_debian7.5LOW
vendor_redhat7.5HIGH
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