CVE-2021-27514Public exploitNetwork attack vector

Authentication bypass via guessable numeric session identifiers

Published Feb 21, 2021 · Updated Aug 3, 2024

Authentication bypass in EyesOfNetwork 5.3-10 allows remote attackers to assume an active user's session by guessing its identifier. The web session handler issues only 8-to-10-digit numeric session_id values, and repeated HTTPS requests accept a guessed value without throttling or binding it to the companion identity cookies. Exploitation requires a currently valid session identifier; the public proof of concept iterates candidate values against the dashboard and reuses a match as an administrator cookie, enabling a separate file-upload flaw to reach code execution.

CVSS severity9.8
Critical
EPSS probability3.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in EyesOfNetwork 5.3-10 allows remote attackers to assume an active user's session by guessing its identifier. The web session handler issues only 8-to-10-digit numeric session_id values, and repeated HTTPS requests accept a guessed value without throttling or binding it to the companion identity cookies. Exploitation requires a currently valid session identifier; the public proof of concept iterates candidate values against the dashboard and reuses a match as an administrator cookie, enabling a separate file-upload flaw to reach code execution.

The record

CVE
CVE-2021-27514
Published
Feb 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-307, CAPEC-49, T1550.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 21, 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

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 exploitPublished

Weakness, pattern, technique

CWE-307Improper Restriction of Excessive Authentication Attempts
CAPEC-49Password Brute Forcing
T1550.004Web Session Cookie

Public exploit references

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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