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Fencer Vulns
high 7.5

CVE-2017-9951 json

The try_read_command function in memcached.c in memcached before 1.4.39 allows remote attackers to cause a denial of service (segmentation…

published 2017-07-17 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-18861

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.2%
EPSS 4.2% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

The try_read_command function in memcached.c in memcached before 1.4.39 allows remote attackers to cause a denial of service (segmentation fault) via a request to add/set a key, which makes a comparison between signed and unsigned int and triggers a heap-based buffer over-read. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-8705.

Patch / fix

  • memcached Debian 14, Debian 13, Debian 12 1.5.0-1

debian advisories DEBIAN-CVE-2017-9951

  • memcached Ubuntu 14.04 LTS 1.4.14-0ubuntu9.2
  • memcached Ubuntu 16.04 LTS 1.4.25-2ubuntu1.3

ubuntu advisories UBUNTU-CVE-2017-9951

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

  • memcached Studio Onsite Runner 1.3, Studio Onsite 1.3, SLE Software Development Kit 11 SP4 1.2.6-5.17.4.1
  • memcached SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2 +3 more 1.4.39-4.3.1
  • memcached OpenStack Cloud 6 1.4.39-3.3.1
  • memcached OpenStack Cloud 7, Enterprise Storage 4 1.4.39-3.3.2

suse advisories SUSE-SU-2018:1601-1SUSE-SU-2018:0839-1SUSE-SU-2018:0807-1SUSE-SU-2018:0778-1

  • memcached openSUSE Tumbleweed 1.6.9-2.3

opensuse advisories openSUSE-SU-2024:11045-1

  • memcached Alpine 3.5, Alpine 3.4, Alpine 3.3 1.4.33-r1
  • memcached Alpine 3.6 1.4.36-r1

alpine advisories ALPINE-CVE-2017-9951

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2017-9951 updated cvss 5.3

memcached: Heap-based buffer over-read in try_read_command function (incomplete fix for CVE-2016-8705)

  • Red Hat Enterprise Linux 6 memcached Red Hat Enterprise Linux 7 memcached Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) memcached Red Hat Mobile Application Platform 4 memcached Red Hat OpenStack Platform 8 (Liberty) memcached Red Hat OpenStack Platform 9 (Mitaka) memcached
    +2 more products
    Red Hat OpenStack Platform 10 (Newton) memcached Red Hat OpenStack Platform 11 (Ocata) memcached
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenStack Platform 12 (Pike) memcached
    not affected: vulnerable code not present

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

4.17% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • twistlock.com https://www.twistlock.com/2017/07/13/cve-2017-9951-heap-overflow-memcached-server-1-4-38-twistlock-vulnerability-report/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

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.