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Fencer Vulns
medium 5.9

CVE-2017-12132 json

The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP r…

published 2017-08-01 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-3716

cvss
5.9
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks due to IP fragmentation.

Patch / fix

  • glibc Debian 14, Debian 13, Debian 12 2.25-1

debian advisories DEBIAN-CVE-2017-12132

  • glibc Ubuntu Pro 16.04 LTS 2.23-0ubuntu11.3+esm3

ubuntu advisories UBUNTU-CVE-2017-12132

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • glibc RHEL 7 2.17-222.el7
  • nscd RHEL 7 2.17-222.el7
  • glibc-utils RHEL 7 2.17-222.el7
  • glibc-common RHEL 7 2.17-222.el7
  • glibc-debuginfo-common RHEL 7 2.17-222.el7

red hat advisories RHSA-2018:0805

  • glibc SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +3 more 2.11.3-17.110.6.2
  • glibc SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2 +6 more 2.22-62.6.2
  • glibc SLES 12-LTSS 2.19-22.27.958
  • glibc SLES for SAP 12 SP1, SLES 12 SP1-LTSS 2.19-40.16.950

suse advisories SUSE-SU-2018:2187-1SUSE-SU-2018:2185-1SUSE-SU-2018:0565-1SUSE-SU-2018:0451-1

  • glibc openSUSE Tumbleweed 2.34-1.2

opensuse advisories openSUSE-SU-2024:10792-1

  • glibc Arch Linux 2.26-1
  • lib32-glibc Arch Linux 2.26-1

arch linux advisories AVG-368AVG-369

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-12132 updated cvss 3.0

glibc: Fragmentation attacks possible when EDNS0 is enabled

  • Red Hat Enterprise Linux 5 glibc, compat-glibc Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, compat-glibc, glibc-common Red Hat Enterprise Linux 7 compat-glibc
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) nscd 2.17-222.el7, glibc 2.17-222.el7, glibc-utils 2.17-222.el7, glibc-common 2.17-222.el7, glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux Client Optional (v. 7) glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux ComputeNode (v. 7) nscd 2.17-222.el7, glibc 2.17-222.el7, glibc-utils 2.17-222.el7, glibc-common 2.17-222.el7, glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) nscd 2.17-222.el7, glibc 2.17-222.el7, glibc-utils 2.17-222.el7, glibc-common 2.17-222.el7, glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) glibc-debuginfo-common 2.17-222.el7
    +4 more products
    Red Hat Enterprise Linux Server (v. 7) nscd 2.17-222.el7, glibc 2.17-222.el7, glibc-utils 2.17-222.el7, glibc-common 2.17-222.el7, glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux Server Optional (v. 7) glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux Workstation (v. 7) nscd 2.17-222.el7, glibc 2.17-222.el7, glibc-utils 2.17-222.el7, glibc-common 2.17-222.el7, glibc-debuginfo-common 2.17-222.el7 Red Hat Enterprise Linux Workstation Optional (v. 7) glibc-debuginfo-common 2.17-222.el7
    fixed: vendor fix RHSA-2018:0805

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.96% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.