CVE-2021-25756Network attack vector

Repository data disclosure via cleartext HTTP links

Published Feb 3, 2021 · Updated Aug 3, 2024

Cleartext repository access in JetBrains IntelliJ IDEA before 2020.2 allows man-in-the-middle attackers to read traffic in transit. Several built-in remote repository links use HTTP instead of HTTPS, leaving requests and responses without transport encryption. Exploitation requires control of the network path; published evidence establishes disclosure, not repository modification or service interruption.

CVSS severity5.3
Medium
EPSS probability1.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext repository access in JetBrains IntelliJ IDEA before 2020.2 allows man-in-the-middle attackers to read traffic in transit. Several built-in remote repository links use HTTP instead of HTTPS, leaving requests and responses without transport encryption. Exploitation requires control of the network path; published evidence establishes disclosure, not repository modification or service interruption.

The record

CVE
CVE-2021-25756
Published
Feb 3, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 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

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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

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.0NVDAV:N/AC:L/Au:N/C:P/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1557Adversary-in-the-Middle

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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