Issued:
2016-05-31
Updated:
2016-05-31

RHSA-2016:1138 - Security Advisory

Synopsis

Moderate: squid security update

Type/Severity

Security Advisory: Moderate

Topic

An update for squid is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Squid is a high-performance proxy caching server for web clients, supporting FTP, Gopher, and HTTP data objects.

Security Fix(es):

  • A buffer overflow flaw was found in the way the Squid cachemgr.cgi utility processed remotely relayed Squid input. When the CGI interface utility is used, a remote attacker could possibly use this flaw to execute arbitrary code. (CVE-2016-4051)
  • Buffer overflow and input validation flaws were found in the way Squid processed ESI responses. If Squid was used as a reverse proxy, or for TLS/HTTPS interception, a remote attacker able to control ESI components on an HTTP server could use these flaws to crash Squid, disclose parts of the stack memory, or possibly execute arbitrary code as the user running Squid. (CVE-2016-4052, CVE-2016-4053, CVE-2016-4054)
  • An input validation flaw was found in Squid's mime_get_header_field() function, which is used to search for headers within HTTP requests. An attacker could send an HTTP request from the client side with specially crafted header Host header that bypasses same-origin security protections, causing Squid operating as interception or reverse-proxy to contact the wrong origin server. It could also be used for cache poisoning for client not following RFC 7230. (CVE-2016-4554)
  • An incorrect reference counting flaw was found in the way Squid processes ESI responses. If Squid is configured as reverse-proxy, for TLS/HTTPS interception, an attacker controlling a server accessed by Squid, could crash the squid worker, causing a Denial of Service attack. (CVE-2016-4556)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing this update, the squid service will be restarted automatically.

Affected Products

  • Red Hat Enterprise Linux Server 6 x86_64
  • Red Hat Enterprise Linux Server 6 i386
  • Red Hat Enterprise Linux Workstation 6 x86_64
  • Red Hat Enterprise Linux Workstation 6 i386
  • Red Hat Enterprise Linux for IBM z Systems 6 s390x
  • Red Hat Enterprise Linux for Power, big endian 6 ppc64

Fixes

  • BZ - 1329126 - CVE-2016-4051 squid: buffer overflow in cachemgr.cgi
  • BZ - 1329136 - CVE-2016-4052 CVE-2016-4053 CVE-2016-4054 squid: multiple issues in ESI processing
  • BZ - 1334241 - CVE-2016-4554 squid: Header Smuggling issue in HTTP Request processing
  • BZ - 1334786 - CVE-2016-4556 squid: SIGSEGV in ESIContext response handling

CVEs

References

Red Hat Enterprise Linux Server 6

SRPM
squid-3.1.23-16.el6_8.4.src.rpm SHA-256: 76903d948e9c282b4793b5f960e5b891e78ee0d392752bd831cc5a191c265f65
x86_64
squid-3.1.23-16.el6_8.4.x86_64.rpm SHA-256: 5c17f3a82a98118ff86823d8e1f478ad04a61f3e296ee2ce80781d5d6d72745d
squid-debuginfo-3.1.23-16.el6_8.4.x86_64.rpm SHA-256: 1d0913ed4a3afc92c75996c519c0cba0a552c076fd9cdb5d32afce9624bacd51
i386
squid-3.1.23-16.el6_8.4.i686.rpm SHA-256: 5b02562e0de3d3fefe6c59919513ffb1f39c8a9e32ba188a8be2066ad3b48e10
squid-debuginfo-3.1.23-16.el6_8.4.i686.rpm SHA-256: 78ff20ea73a3879796688b1b4229584026450a9c3966dbd0df4d755de3250270

Red Hat Enterprise Linux Workstation 6

SRPM
squid-3.1.23-16.el6_8.4.src.rpm SHA-256: 76903d948e9c282b4793b5f960e5b891e78ee0d392752bd831cc5a191c265f65
x86_64
squid-3.1.23-16.el6_8.4.x86_64.rpm SHA-256: 5c17f3a82a98118ff86823d8e1f478ad04a61f3e296ee2ce80781d5d6d72745d
squid-debuginfo-3.1.23-16.el6_8.4.x86_64.rpm SHA-256: 1d0913ed4a3afc92c75996c519c0cba0a552c076fd9cdb5d32afce9624bacd51
i386
squid-3.1.23-16.el6_8.4.i686.rpm SHA-256: 5b02562e0de3d3fefe6c59919513ffb1f39c8a9e32ba188a8be2066ad3b48e10
squid-debuginfo-3.1.23-16.el6_8.4.i686.rpm SHA-256: 78ff20ea73a3879796688b1b4229584026450a9c3966dbd0df4d755de3250270

Red Hat Enterprise Linux for IBM z Systems 6

SRPM
squid-3.1.23-16.el6_8.4.src.rpm SHA-256: 76903d948e9c282b4793b5f960e5b891e78ee0d392752bd831cc5a191c265f65
s390x
squid-3.1.23-16.el6_8.4.s390x.rpm SHA-256: 0545aed963d3dddc669bc87c80af709dd3964f5b2be8309bad70170d35b8e092
squid-debuginfo-3.1.23-16.el6_8.4.s390x.rpm SHA-256: 37c53d3282a5e98b93386428454c697226a05fb9cead3dd177667c2dae78844d

Red Hat Enterprise Linux for Power, big endian 6

SRPM
squid-3.1.23-16.el6_8.4.src.rpm SHA-256: 76903d948e9c282b4793b5f960e5b891e78ee0d392752bd831cc5a191c265f65
ppc64
squid-3.1.23-16.el6_8.4.ppc64.rpm SHA-256: 3884aaca32fbbe31b98cef3e4952a6acd0d334c3dff6a3fa8d3cef2248fcf971
squid-debuginfo-3.1.23-16.el6_8.4.ppc64.rpm SHA-256: b4ecc524814e607fdbc0ee297f334e847dd8fc8d2a12510c8962e3293b04c4fb

The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.