CVE-2013-4235: shadow: TOCTOU (time-of-check time-of-use) race condition when copying and removing directory trees

Routine

MEDIUM 4.7WATCHLISTMITIGATEMITIGATEMITIGATE

CVE-2013-4235 is a medium-severity flaw (CVSS 4.7) affecting shadow, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

shadow: TOCTOU (time-of-check time-of-use) race condition when copying and removing directory trees

Why this priority

On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-367
Published	2019-12-03
Last modified	2026-10-14

Publisher (CNA): Red Hat, Inc. · Vendor: debian · fedoraproject · redhat

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-12-03 15:15 UTCPublished CVE record published
2026-10-14 07:16 UTCUpdated Record last modified

debian shadow MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy shadow || rpm -q shadow || shadow --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

debian debian linux MITIGATE

Affected: 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

fedoraproject fedora MITIGATE

Affected: 16 · 17

Fixed in: no fixed release known

Safe to downgrade to: a release before 16

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux MITIGATE

Affected: 5 · 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2013-4235?

shadow: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2013-4235 being exploited?

CVE-2013-4235 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2013-4235 affect?

CVE-2013-4235 affects shadow, debian linux, fedora. Severity is medium (CVSS 4.7). shadow: TOCTOU (time-of-check time-of-use) race condition when copying and removing directory trees

How urgent is CVE-2013-4235?

Priority 27/100. On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

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CVE-2019-16110 HIGH 8.1 UPGRADE The network protocol of Blade Shadow though 2.13.3 allows remote attackers to take control of a Shadow instanc
CVE-2018-7169 MEDIUM 5.3 DOWNGRADE An issue was discovered in shadow 4.5
CVE-2018-16588 HIGH 7.8 UPGRADE Privilege escalation can occur in the SUSE useradd.c code in useradd, as distributed in the SUSE shadow packag
CVE-2017-20002 HIGH 7.8 DOWNGRADE MITIGATE The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in

References

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