CVE-2015-5400
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with...
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
Exploit likelihood
What each source reports
NVD Score used
6.8
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
CVE-2015-5400- CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-264
- Updated
- 2026-11-02
CVE List No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
CVE-2015-5400- Updated
- 2026-11-02
EUVDEUVD-2015-5356 No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
EUVD-2015-5356- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9pj4-fqm8-w5x7 No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with...
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
GHSA-9pj4-fqm8-w5x7- Updated
- 2026-11-02
OSV No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
CVE-2015-5400- Updated
- 2026-11-02
OSVDEBIAN-CVE-2015-5400 No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
DEBIAN-CVE-2015-5400- Updated
- 2026-11-02
Show 5 moreShow less
OSVMGASA-2015-0347 No score
Updated squid packages fix CVE-2015-5400
Updated squid packages fix security vulnerability:
Alex Rousskov discovered that Squid configured with cache_peer and operating on explicit proxy traffic does not correctly handle CONNECT method peer responses. In some configurations, it allows remote clients to bypass security in an explicit gateway proxy (CVE-2015-5400).
- Record
MGASA-2015-0347- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:10307-1 No score
squid-3.5.22-1.1 on GA media
These are all security issues fixed in the squid-3.5.22-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10307-1- Updated
- 2026-11-02
OSVSUSE-SU-2016:2008-1 No score
Security update for squid
The Squid HTTP proxy has been updated to version 3.3.14, fixing the following security issues:
- Fixed multiple Denial of Service issues in HTTP Response processing. (CVE-2016-2569, CVE-2016-2570, CVE-2016-2571, CVE-2016-2572, bsc#968392, bsc#968393, bsc#968394, bsc#968395)
- CVE-2016-3947: Buffer overrun issue in pinger ICMPv6 processing. (bsc#973782)
- CVE-2015-5400: Improper protection of alternate path. (bsc#938715)
- CVE-2015-3455: Squid http proxy configured with client-first SSL bumping did not correctly validate server certificate. (bsc#929493)
- CVE-2016-3948: Fixed denial of service in HTTP Response processing (bsc#973783)
- CVE-2016-4051: fixes buffer overflow in cachemgr.cgi (bsc#976553)
- CVE-2016-4052, CVE-2016-4053, CVE-2016-4054: Fixed multiple issues in ESI processing (bsc#976556)
- CVE-2016-4553: Fixed cache poisoning issue in HTTP Request handling (bsc#979009)
- CVE-2016-4554: Fixed header smuggling issue in HTTP Request processing (bsc#979010)
- Fixed multiple Denial of Service issues in ESI Response processing. (CVE-2016-4555, CVE-2016-4556, bsc#979011, bsc#979008)
Additionally, the following non-security issues have been fixed:
- Fix header size in script unsquid.pl. (bsc#902197)
- Add external helper ext_session_acl to package. (bsc#959290)
- Update forward_max_tries to permit 25 server paths With cloud sites becoming more popular more CDN servers are producing long lists of IPv6 and IPv4 addresses. If there are not enough paths selected the IPv4 ones may never be reached.
- squid.init: wait that squid really dies when we kill it on upgrade instead of proclaiming its demise prematurely (bnc#963539)
- Record
SUSE-SU-2016:2008-1- Updated
- 2026-11-02
OSVSUSE-SU-2016:2089-1 No score
Security update for squid3
This update for squid3 fixes the following issues:
-
Multiple issues in pinger ICMP processing. (CVE-2014-7141, CVE-2014-7142)
-
CVE-2016-3947: Buffer overrun issue in pinger ICMPv6 processing. (bsc#973782)
-
CVE-2016-4554: fix header smuggling issue in HTTP Request processing (bsc#979010)
-
Fix multiple Denial of Service issues in HTTP Response processing. (CVE-2016-2569, CVE-2016-2570, CVE-2016-2571, CVE-2016-2572, bsc#968392, bsc#968393, bsc#968394, bsc#968395)
-
Regression caused by the DoS fixes above (bsc#993299)
-
CVE-2016-3948: Fix denial of service in HTTP Response processing (bsc#973783)
-
CVE-2016-4051: fixes buffer overflow in cachemgr.cgi (bsc#976553)
-
CVE-2016-4052, CVE-2016-4053, CVE-2016-4054:
- fixes multiple issues in ESI processing (bsc#976556)
-
CVE-2016-4556: fixes double free vulnerability in Esi.cc (bsc#979008)
-
CVE-2015-5400: Improper Protection of Alternate Path (bsc#938715)
-
CVE-2014-6270: fix off-by-one in snmp subsystem (bsc#895773)
-
Memory leak in squid3 when using external_acl (bsc#976708)
- Record
SUSE-SU-2016:2089-1- Updated
- 2026-11-02
OSVUBUNTU-CVE-2015-5400 No score
Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
- Record
UBUNTU-CVE-2015-5400- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
squidDebian:12 |
before 4.1-1 | 4.1-1 |
squidDebian:13 |
before 4.1-1 | 4.1-1 |
squidDebian:14 |
before 4.1-1 | 4.1-1 |
squid3Debian:6.0 |
before 3.1.6-1.2+squeeze5, plus listed versions 3.1.6-1.23.1.6-1.2+squeeze13.1.6-1.2+squeeze23.1.6-1.2+squeeze33.1.6-1.2+squeeze4 |
3.1.6-1.2+squeeze5 |
squid3Debian:7 |
before 3.1.20-2.2+deb7u3, plus listed versions 3.1.20-2.23.1.20-2.2+deb7u13.1.20-2.2+deb7u2 |
3.1.20-2.2+deb7u3 |
squid3Debian:8 |
before 3.4.8-6+deb8u1, plus listed versions 3.4.8-6 |
3.4.8-6+deb8u1 |
squidMageia:5 |
before 3.4.13-1.1.mga5 | 3.4.13-1.1.mga5 |
squidSUSE:Linux Enterprise Server 12 SP1 From an advisory covering 16 CVEs |
before 3.3.14-20.2 | 3.3.14-20.2 |
squidSUSE:Linux Enterprise Server for SAP Applications 12 SP1 From an advisory covering 16 CVEs |
before 3.3.14-20.2 | 3.3.14-20.2 |
squid3SUSE:Linux Enterprise Server 11 SP4 From an advisory covering 25 CVEs |
before 3.1.23-8.16.30.1 | 3.1.23-8.16.30.1 |
squid3SUSE:Linux Enterprise Server for SAP Applications 11 SP4 From an advisory covering 25 CVEs |
before 3.1.23-8.16.30.1 | 3.1.23-8.16.30.1 |
squid3Ubuntu:16.04:LTS |
before 3.5.12-1ubuntu6, plus listed versions 3.3.8-1ubuntu163.3.8-1ubuntu17 |
3.5.12-1ubuntu6 |
squidopenSUSE:Tumbleweed From an advisory covering 4 CVEs |
before 3.5.22-1.1 | 3.5.22-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2015-5400 is a medium vulnerability (CVSS 6.8) in Squid-cache Squid, published July 30, 2015. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 20.8%, the 97th percentile. Fixed in squid 4.1-1.
References
openwall.com/lists/oss-security/2015/07/06/8
securitytracker.com/id/1032873
lists.fedoraproject.org/pipermail/package-announce/2016-May/183598.html
squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patch
lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
openwall.com/lists/oss-security/2015/07/17/14
Show 66 moreShow less
openwall.com/lists/oss-security/2015/07/09/12
lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patch
openwall.com/lists/oss-security/2015/07/10/2
lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
squid-cache.org/Advisories/SQUID-2015_2.txt
debian.org/security/2015/dsa-3327
securityfocus.com/bid/75553
squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patch
nvd.nist.gov/vuln/detail/CVE-2015-5400
github.com/advisories/GHSA-9pj4-fqm8-w5x7
security-tracker.debian.org/tracker/CVE-2015-5400
advisories.mageia.org/MGASA-2015-0347.html
bugs.mageia.org/show_bug.cgi?id=16304
suse.com/support/update/announcement/2016/suse-su-20162008-1
bugzilla.suse.com/902197
bugzilla.suse.com/929493
bugzilla.suse.com/938715
bugzilla.suse.com/955783
bugzilla.suse.com/959290
bugzilla.suse.com/963539
bugzilla.suse.com/968392
bugzilla.suse.com/968393
bugzilla.suse.com/968394
bugzilla.suse.com/968395
bugzilla.suse.com/973782
bugzilla.suse.com/973783
bugzilla.suse.com/976553
bugzilla.suse.com/976556
bugzilla.suse.com/979008
bugzilla.suse.com/979009
bugzilla.suse.com/979010
bugzilla.suse.com/979011
suse.com/security/cve/CVE-2015-3455
suse.com/security/cve/CVE-2015-5400
suse.com/security/cve/CVE-2016-2569
suse.com/security/cve/CVE-2016-2570
suse.com/security/cve/CVE-2016-2571
suse.com/security/cve/CVE-2016-2572
suse.com/security/cve/CVE-2016-3947
suse.com/security/cve/CVE-2016-3948
suse.com/security/cve/CVE-2016-4051
suse.com/security/cve/CVE-2016-4052
suse.com/security/cve/CVE-2016-4053
suse.com/security/cve/CVE-2016-4054
suse.com/security/cve/CVE-2016-4553
suse.com/security/cve/CVE-2016-4554
suse.com/security/cve/CVE-2016-4555
suse.com/security/cve/CVE-2016-4556
suse.com/support/update/announcement/2016/suse-su-20162089-1
bugzilla.suse.com/895773
bugzilla.suse.com/967011
bugzilla.suse.com/976708
bugzilla.suse.com/993299
suse.com/security/cve/CVE-2011-3205
suse.com/security/cve/CVE-2011-4096
suse.com/security/cve/CVE-2012-5643
suse.com/security/cve/CVE-2013-0188
suse.com/security/cve/CVE-2013-4115
suse.com/security/cve/CVE-2014-0128
suse.com/security/cve/CVE-2014-6270
suse.com/security/cve/CVE-2014-7141
suse.com/security/cve/CVE-2014-7142
suse.com/security/cve/CVE-2016-2390
ubuntu.com/security/CVE-2015-5400
cve.org/CVERecord?id=CVE-2015-5400