CVE-2021-39158Network attack vector

Code execution via unclaimed Python dependency

Published Aug 23, 2021 · Updated Aug 4, 2024

Dependency confusion in NVIDIA Caffe before 0.17.4 allows remote attackers to execute code when a user installs Python requirements. The Python requirements list names gfortran as a PyPI dependency although no such distribution existed, allowing an attacker-controlled package to satisfy the unverified name. Exploitation requires an attacker to claim that name on PyPI and a user to install the affected requirements, which executes the package's installation code.

CVSS severity8.8
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Dependency confusion in NVIDIA Caffe before 0.17.4 allows remote attackers to execute code when a user installs Python requirements. The Python requirements list names gfortran as a PyPI dependency although no such distribution existed, allowing an attacker-controlled package to satisfy the unverified name. Exploitation requires an attacker to claim that name on PyPI and a user to install the affected requirements, which executes the package's installation code.

The record

CVE
CVE-2021-39158
Published
Aug 23, 2021
Updated
Aug 4, 2024
Vendor
NVIDIA
Product
NVIDIA Caffe
Classifications
CWE-345, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

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

  1. Affected versionversion=<= 0.17.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NVIDIA · NVIDIA Caffeversion=<= 0.17.4

Published CVSS scores

8.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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-345Insufficient Verification of Data Authenticity
T1195.001Compromise Software Dependencies and Development Tools

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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