CVE-2021-3115Network attack vector

Arbitrary code execution via cgo compiler path hijacking

Published Jan 26, 2021 · Updated Aug 3, 2024

Command injection in Go before 1.14.14 and 1.15.0 through 1.15.6 on Windows allows remote attackers to execute code during cgo builds. The cgo tool resolves the host C compiler from an untrusted package directory, causing Windows path lookup to prefer an attacker-supplied gcc.exe. Exploitation requires a user to fetch or build a malicious cgo package, after which the bundled executable runs with that user's privileges.

CVSS severity7.5
High
EPSS probability6.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Go before 1.14.14 and 1.15.0 through 1.15.6 on Windows allows remote attackers to execute code during cgo builds. The cgo tool resolves the host C compiler from an untrusted package directory, causing Windows path lookup to prefer an attacker-supplied gcc.exe. Exploitation requires a user to fetch or build a malicious cgo package, after which the bundled executable runs with that user's privileges.

The record

CVE
CVE-2021-3115
Published
Jan 26, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-427, T1574.007, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
5.1NIST National Vulnerability DatabaseAV:N/AC:H/Au:N/C:P/I:P/A:P
7.3SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
T1574.007Hijack Execution Flow: PATH Environment Variable
T1204.002User Execution: Malicious File

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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