CVE-2016-3948
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows...
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
7.5
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
CVE-2016-3948- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-119
- Updated
- 2026-11-02
CVE List No score
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
CVE-2016-3948- Updated
- 2026-11-02
EUVDEUVD-2016-4960 No score
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
EUVD-2016-4960- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f5f6-9f53-wf3r
7.5
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows...
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
GHSA-f5f6-9f53-wf3r- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
OSV
7.5
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
CVE-2016-3948- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2016-3948
7.5
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
DEBIAN-CVE-2016-3948- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 5 moreShow less
OSVUBUNTU-CVE-2016-3948
7.5
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
- Record
UBUNTU-CVE-2016-3948- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2016-0133 No score
Updated squid packages fix security vulnerabilities
Updated squid packages fix security vulnerabilities:
Due to a buffer overrun, the Squid pinger binary in Squid before 3.5.16 is vulnerable to a denial of service or information leak attack when processing ICMPv6 packets. This bug also permits the server response to manipulate other ICMP and ICMPv6 queries processing to cause information leaks (CVE-2016-3947).
Due to incorrect bounds checking, Squid before 3.5.16 is vulnerable to a denial of service attack when processing HTTP responses (CVE-2016-3948).
- Record
MGASA-2016-0133- 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
OSVUSN-3557-1 No score
squid3 vulnerabilities
Mathias Fischer discovered that Squid incorrectly handled certain long strings in headers. A malicious remote server could possibly cause Squid to crash, resulting in a denial of service. This issue was only addressed in Ubuntu 16.04 LTS. (CVE-2016-2569)
William Lima discovered that Squid incorrectly handled XML parsing when processing Edge Side Includes (ESI). A malicious remote server could possibly cause Squid to crash, resulting in a denial of service. This issue was only addressed in Ubuntu 16.04 LTS. (CVE-2016-2570)
Alex Rousskov discovered that Squid incorrectly handled response-parsing failures. A malicious remote server could possibly cause Squid to crash, resulting in a denial of service. This issue only applied to Ubuntu 16.04 LTS. (CVE-2016-2571)
Santiago Ruano Rincón discovered that Squid incorrectly handled certain Vary headers. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue was only addressed in Ubuntu 16.04 LTS. (CVE-2016-3948)
Louis Dion-Marcil discovered that Squid incorrectly handled certain Edge Side Includes (ESI) responses. A malicious remote server could possibly cause Squid to crash, resulting in a denial of service. (CVE-2018-1000024)
Louis Dion-Marcil discovered that Squid incorrectly handled certain Edge Side Includes (ESI) responses. A malicious remote server could possibly cause Squid to crash, resulting in a denial of service. (CVE-2018-1000027)
- Record
USN-3557-1- 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:8 From an advisory covering 9 CVEs |
before 3.4.8-6+deb8u3, plus listed versions 3.4.8-63.4.8-6+deb8u13.4.8-6+deb8u23.4.8-6+deb8u2~bpo70+1 |
3.4.8-6+deb8u3 |
squidMageia:5 From an advisory covering 2 CVEs |
before 3.5.16-1.mga5 | 3.5.16-1.mga5 |
squid-debuginfoRed Hat:enterprise_linux:7::server From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squid-sysvinitRed Hat:enterprise_linux:7::server From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squidRed Hat:enterprise_linux:7::server From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squid-migration-scriptRed Hat:enterprise_linux:7::server From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squid-debuginfoRed Hat:enterprise_linux:7::workstation From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
Show 10 moreShow less
| Package | Affected | Fixed |
|---|---|---|
squid-sysvinitRed Hat:enterprise_linux:7::workstation From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squidRed Hat:enterprise_linux:7::workstation From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
squid-migration-scriptRed Hat:enterprise_linux:7::workstation From an advisory covering 5 CVEs |
before 7:3.5.20-2.el7 | 7:3.5.20-2.el7 |
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 3.5.12-1ubuntu7.5, plus listed versions 3.3.8-1ubuntu163.3.8-1ubuntu173.5.12-1ubuntu63.5.12-1ubuntu73.5.12-1ubuntu7.13.5.12-1ubuntu7.23.5.12-1ubuntu7.33.5.12-1ubuntu7.4 |
3.5.12-1ubuntu7.5 |
squid3Ubuntu:14.04:LTS From an advisory covering 6 CVEs |
before 3.3.8-1ubuntu6.11, plus listed versions 3.3.8-1ubuntu33.3.8-1ubuntu43.3.8-1ubuntu53.3.8-1ubuntu63.3.8-1ubuntu6.1 Show 7 moreShow less3.3.8-1ubuntu6.23.3.8-1ubuntu6.33.3.8-1ubuntu6.43.3.8-1ubuntu6.63.3.8-1ubuntu6.83.3.8-1ubuntu6.93.3.8-1ubuntu6.10 |
3.3.8-1ubuntu6.11 |
squid3Ubuntu:16.04:LTS From an advisory covering 6 CVEs |
before 3.5.12-1ubuntu7.5, plus listed versions 3.3.8-1ubuntu163.3.8-1ubuntu173.5.12-1ubuntu63.5.12-1ubuntu73.5.12-1ubuntu7.13.5.12-1ubuntu7.23.5.12-1ubuntu7.33.5.12-1ubuntu7.4 |
3.5.12-1ubuntu7.5 |
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-2016-3948 is a high vulnerability (CVSS 7.5) in Squid-cache Squid, published April 6, 2016. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 35.3%, the 98th percentile. Fixed in squid 4.1-1.
References
usn.ubuntu.com/3557-1
security.gentoo.org/glsa/201607-01
squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14016.patch
lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
rhn.redhat.com/errata/RHSA-2016-2600.html
securitytracker.com/id/1035458
Show 93 moreShow less
lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
squid-cache.org/Advisories/SQUID-2016_4.txt
nvd.nist.gov/vuln/detail/CVE-2016-3948
github.com/advisories/GHSA-f5f6-9f53-wf3r
security-tracker.debian.org/tracker/CVE-2016-3948
advisories.mageia.org/MGASA-2016-0133.html
bugs.mageia.org/show_bug.cgi?id=18122
squid-cache.org/Advisories/SQUID-2016_3.txt
access.redhat.com/errata/RHSA-2016:2600
access.redhat.com/security/updates/classification
access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/7.3_Release_Notes/index.html
bugzilla.redhat.com/show_bug.cgi?id=1254016
bugzilla.redhat.com/show_bug.cgi?id=1254018
bugzilla.redhat.com/show_bug.cgi?id=1299972
bugzilla.redhat.com/show_bug.cgi?id=1312257
bugzilla.redhat.com/show_bug.cgi?id=1312262
bugzilla.redhat.com/show_bug.cgi?id=1323594
bugzilla.redhat.com/show_bug.cgi?id=1330186
bugzilla.redhat.com/show_bug.cgi?id=1336940
security.access.redhat.com/data/csaf/v2/advisories/2016/rhsa-2016_2600.json
access.redhat.com/security/cve/CVE-2016-2569
cve.org/CVERecord?id=CVE-2016-2569
nvd.nist.gov/vuln/detail/CVE-2016-2569
squid-cache.org/Advisories/SQUID-2016_2.txt
access.redhat.com/security/cve/CVE-2016-2570
cve.org/CVERecord?id=CVE-2016-2570
nvd.nist.gov/vuln/detail/CVE-2016-2570
access.redhat.com/security/cve/CVE-2016-2571
cve.org/CVERecord?id=CVE-2016-2571
nvd.nist.gov/vuln/detail/CVE-2016-2571
access.redhat.com/security/cve/CVE-2016-2572
cve.org/CVERecord?id=CVE-2016-2572
nvd.nist.gov/vuln/detail/CVE-2016-2572
access.redhat.com/security/cve/CVE-2016-3948
cve.org/CVERecord?id=CVE-2016-3948
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-2016-3948
ubuntu.com/security/notices/USN-3557-1
ubuntu.com/security/CVE-2016-2569
ubuntu.com/security/CVE-2016-2570
ubuntu.com/security/CVE-2016-2571
ubuntu.com/security/CVE-2018-1000024
ubuntu.com/security/CVE-2018-1000027