CVE-2021-29428 — Local privilege escalation through system temporary directory
In Gradle before version 7.0, on Unix-like systems, the system temporary directory can be created with open permissions that allow multiple users to create and delete files within it. Gradle builds could be vulnerable to a local privilege escalation from an attacker quickly deleting and recreating files in the system temporary directory. This vulnerability impacted builds using precompiled script plugins written in Kotlin DSL and tests for Gradle plugins written using ProjectBuilder or TestKit. If you are on Windows or modern versions of macOS, you are not vulnerable. If you are on a Unix-like operating system with the "sticky" bit set on your system temporary directory, you are not vulnerable. The problem has been patched and released with Gradle 7.0. As a workaround, on Unix-like operating systems, ensure that the "sticky" bit is set. This only allows the original user (or root) to delete a file. If you are unable to change the permissions of the system temporary directory, you can move the Java temporary directory by setting the System Property `java.io.tmpdir`. The new path needs to limit permissions to the build user only. For additional details refer to the referenced GitHub Security Advisory.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+7
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Gradle Gradle, Quarkus Quarkus).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.0 | 6.0 | security-advisories@github.com via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 4.4 | CVSS 2.0 | Medium | 3.4 | 6.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.54%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · gradle/gradle
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2021
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-50559 Authentication/Authorization Bypass via Advanced Path Normalization Vulnerabilities Jun 19, 2026
- High CVE-2026-39852 Quarkus authorization bypass via semicolon path normalization inconsistency May 5, 2026
- High CVE-2026-22865 Gradle's failure to disable repositories failing to answer can expose builds to malicious artifacts Jan 16, 2026
- High CVE-2026-22816 Gradle fails to disable repositories which can expose builds to malicious artifacts Jan 16, 2026
- High CVE-2025-66560 Quarkus REST has potential worker thread starvation when HTTP connection is closed while waiting to write Jan 7, 2026
- Medium CVE-2023-44387 Gradle has incorrect permission assignment for symlinked files used in copy or archiving operations Oct 5, 2023
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-29428 is "Local privilege escalation through system temporary directory", rated High. It affects Gradle (Gradle); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.54% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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