CVE-2021-28153Public exploitNetwork attack vector

Empty-file creation via dangling-symlink replacement

Published Mar 11, 2021 · Updated Aug 3, 2024

Improper link resolution in GNOME GLib before 2.66.8 allows attackers to create an empty file through an attacker-controlled dangling symlink. When g_file_replace() receives G_FILE_CREATE_REPLACE_DESTINATION, it follows a dangling link and creates its nonexistent target instead of replacing only the link path. The caller must use that flag on an attacker-controlled dangling symlink; an existing target remains unchanged, limiting the direct consequence to creation of an empty file at an absent target.

CVSS severity5.3
Medium
EPSS probability2.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper link resolution in GNOME GLib before 2.66.8 allows attackers to create an empty file through an attacker-controlled dangling symlink. When g_file_replace() receives G_FILE_CREATE_REPLACE_DESTINATION, it follows a dangling link and creates its nonexistent target instead of replacing only the link path. The caller must use that flag on an attacker-controlled dangling symlink; an existing target remains unchanged, limiting the direct consequence to creation of an empty file at an absent target.

The record

CVE
CVE-2021-28153
Published
Mar 11, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-59, CAPEC-132, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
CAPEC-132Symlink Attack
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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