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Fencer Vulns
medium 6.4

CVE-2017-7549 json

instack-undercloud vulnerable to symlink attack on tmp files

published 2017-09-21 9 y ago modified 2026-07-06 4 mo ago also GHSA-53wm-97p6-582f , PYSEC-2017-152 , PYSEC-2026-645 , EUVD-2022-2488

cvss
6.4
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

A flaw was found in instack-undercloud 7.2.0 as packaged in Red Hat OpenStack Platform Pike, 6.1.0 as packaged in Red Hat OpenStack Platform Oacta, 5.3.0 as packaged in Red Hat OpenStack Newton, where pre-install and security policy scripts used insecure temporary files. A local user could exploit this flaw to conduct a symbolic-link attack, allowing them to overwrite the contents of arbitrary files.

Patch / fix

  • instack-undercloud openstack 10 5.3.0-3.el7ost
  • instack-undercloud openstack-director 9 4.0.0-17.el7ost
  • instack-undercloud openstack-director 8 2.2.7-10.el7ost
  • instack-undercloud openstack-director 7 2.1.2-41.el7ost
  • instack-undercloud openstack 11 6.1.0-3.el7ost

red hat advisories RHSA-2017:2649RHSA-2017:2557RHSA-2017:2687RHSA-2017:2693RHSA-2017:2726

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-2017-7549 updated cvss 6.1

instack-undercloud: uses hardcoded /tmp paths

  • Red Hat Enterprise Linux OpenStack Platform 6 (Juno) instack-undercloud
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) instack-undercloud Red Hat OpenStack Platform 8 (Liberty) instack-undercloud Red Hat OpenStack Platform 9 (Mitaka) instack-undercloud
    affected: no fix available
  • Red Hat OpenStack 7.0 Director for RHEL 7 instack-undercloud 2.1.2-41.el7ost
    fixed: vendor fix RHSA-2017:2693
  • Red Hat OpenStack 8.0 Director for RHEL 7 instack-undercloud 2.2.7-10.el7ost
    fixed: vendor fix RHSA-2017:2687
  • Red Hat OpenStack 9.0 Director for RHEL 7 instack-undercloud 4.0.0-17.el7ost
    fixed: vendor fix RHSA-2017:2557
  • Red Hat OpenStack Platform 10.0 instack-undercloud 5.3.0-3.el7ost
    fixed: vendor fix RHSA-2017:2649
  • Red Hat OpenStack Platform 11.0 instack-undercloud 6.1.0-3.el7ost
    fixed: vendor fix RHSA-2017:2726
  • Red Hat OpenStack Platform 12 (Pike) instack-undercloud
    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

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 6.4 CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
NVD 2.0 3.3 AV:L/AC:M/Au:N/C:P/I:P/A:N
OSV 3.0 6.4 CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
GitHub 3.0 6.4 CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
pypi instack-undercloud
<=7.2.0
 no fix listed
pypi instack
<=7.2.0
<=6.1.0
<=5.3.0
 no fix listed

Affected products

  • Red Hat, Inc. instack-undercloud

Classification

Weakness
  • CWE-377 DEPRECATED: Insecure Temporary File
  • CWE-59 Improper Link Resolution Before File Access

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.