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Fencer Vulns
high 8.1

CVE-2023-39323 json

Arbitrary code execution during build via line directives in cmd/go

published 2023-10-05 3 y ago modified 2026-09-08 2 mo ago also BIT-golang-2023-39323 , EUVD-2023-43055 , GO-2023-2095

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits
0
none known

Summary

Line directives ("//line") can be used to bypass the restrictions on "//go:cgo_" directives, allowing blocked linker and compiler flags to be passed during compilation. This can result in unexpected execution of arbitrary code when running "go build". The line directive requires the absolute path of the file in which the directive lives, which makes exploiting this issue significantly more complex.

Patch / fix

  • bitnami golang 1.20.9, 1.21.2
  • go toolchain 1.20.9, 1.21.2
  • Go toolchain cmd/go 1.20.9, 1.21.2
  • golang-1.17 Ubuntu 22.04 LTS 1.17.13-3ubuntu1.3
  • golang-1.18 Ubuntu 20.04 LTS 1.18.1-1ubuntu1~20.04.3
  • golang-1.18 Ubuntu 22.04 LTS 1.18.1-1ubuntu1.2
  • golang-1.20 Ubuntu 20.04 LTS 1.20.3-1ubuntu0.1~20.04.1
  • golang-1.20 Ubuntu 22.04 LTS 1.20.3-1ubuntu0.1~22.04.1
  • golang-1.21 Ubuntu 20.04 LTS 1.21.1-1~ubuntu20.04.2
  • golang-1.21 Ubuntu 22.04 LTS 1.21.1-1~ubuntu22.04.2
  • golang-1.18 Ubuntu Pro 16.04 LTS 1.18.1-1ubuntu1~16.04.6+esm1

ubuntu advisories UBUNTU-CVE-2023-39323

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • delve RHEL 8 1.20.2-1.module+el8.9.0+18926+5193682d
  • golang RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80
  • go-toolset RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80
  • golang-bin RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80
  • golang-src RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80
  • golang-misc RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80
  • golang-tests RHEL 8 1.20.10-1.module+el8.9.0+20382+04f7fe80

red hat advisories RHBA-2023:6928

  • go1.20-openssl SLE Module for Development Tools 15 SP5, SLE Module for Development Tools 15 SP4, openSUSE Leap 15.5 +1 more 1.20.11.1-150000.1.14.1
  • go1.21-openssl SLE Module for Development Tools 15 SP5, SLE Module for Development Tools 15 SP4, openSUSE Leap 15.5 +1 more 1.21.4.1-150000.1.5.1
  • go1.20 SLE Module for Development Tools 15 SP5, SLE Module for Development Tools 15 SP4, openSUSE Leap 15.5 +1 more 1.20.9-150000.1.26.1
  • go1.21 SLE Module for Development Tools 15 SP5, SLE Module for Development Tools 15 SP4, openSUSE Leap 15.5 +1 more 1.21.2-150000.1.9.1

suse advisories SUSE-SU-2023:4472-1SUSE-SU-2023:4469-1SUSE-SU-2023:4018-1SUSE-SU-2023:4017-1

  • go1.20 openSUSE Tumbleweed 1.20.9-1.1
  • go1.21 openSUSE Tumbleweed 1.21.2-1.1
  • go1.21 Package Hub 12 1.21.3-2.1
  • go Package Hub 12 1.21-41.1

opensuse advisories openSUSE-SU-2024:13306-1openSUSE-SU-2024:13307-1openSUSE-SU-2023:0360-1

  • go Alpine 3.18 1.20.9-r0
  • go Alpine 3.24, Alpine 3.23, Alpine 3.22 +3 more 1.21.2-r0

alpine advisories ALPINE-CVE-2023-39323

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • golang CBL-Mariner 2.0, Azure Linux 3.0 1.20.10-1
  • golang CBL-Mariner 2.0 1.21.6-1

azure linux advisories AZL-31107AZL-37358AZL-37389AZL-52845

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-39323 updated cvss 8.1

golang: cmd/go: line directives allows arbitrary execution during build

  • Red Hat Enterprise Linux 9 golang, go-toolset, golang-bin, golang-src, golang-misc, golang-race, +1 more Red Hat OpenShift Virtualization 4 openshift-golang-builder-container
    affected: no fix available
  • Red Hat Storage 3 golang, golang-bin, golang-src, golang-misc, golang-tests, go-toolset-7-golang
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 8) ubi8/go-toolset 1.20.10-3, rhel8/go-toolset 1.20.10-3, delve 1.20.2-1.module+el8.9.0+18926+5193682d, golang 1.20.10-1.module+el8.9.0+20382+04f7fe80, go-toolset 1.20.10-1.module+el8.9.0+20382+04f7fe80, golang-bin 1.20.10-1.module+el8.9.0+20382+04f7fe80, +3 more
    fixed: vendor fix RHBA-2023:6928
  • Red Hat OpenShift Service Mesh 2 openshift-golang-builder-container Red Hat OpenShift Container Platform 4 openshift-golang-builder-container
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
16 mo ago

Exploit prediction

1.91% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
bitnami golang
<1.20.9
>=1.21.0, <1.21.2
1.20.9
1.21.2
go toolchain
<1.20.9
>=1.21.0-0, <1.21.2
1.20.9
1.21.2

Affected products

  • Go toolchain cmd/go

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.