CVE-2021-3978

Local privilege escalation via preserved setuid bits

Published Jan 29, 2025 · Updated Feb 12, 2025

Improper permission preservation in Cloudflare OctoRPKI before 1.4.2 allows local users to gain root privileges through malicious TAL content. The validator invokes rsync with archive mode while running as root, so an attacker-controlled binary retains its setuid bit when copied. Exploitation requires low-privileged local access, user interaction, and a separate flaw that makes OctoRPKI process the malicious TAL file; successful chaining grants root-level control.

CVSS severity7.5
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper permission preservation in Cloudflare OctoRPKI before 1.4.2 allows local users to gain root privileges through malicious TAL content. The validator invokes rsync with archive mode while running as root, so an attacker-controlled binary retains its setuid bit when copied. Exploitation requires low-privileged local access, user interaction, and a separate flaw that makes OctoRPKI process the malicious TAL file; successful chaining grants root-level control.

The record

CVE
CVE-2021-3978
Published
Jan 29, 2025
Updated
Feb 12, 2025
Vendor
Cloudflare
Product
OctoRPKI
Classifications
CWE-281, CWE-269, CAPEC-233, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <v1.4.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Cloudflare · OctoRPKIversion=0 <v1.4.2

Published CVSS scores

7.5CloudflareCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-281Improper Preservation of Permissions
CWE-269Improper Privilege Management
CAPEC-233Privilege Escalation
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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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