CVE-2025-40925Network attack vector

Session hijacking via predictable state identifiers

Published Sep 20, 2025 · Updated Sep 20, 2025

Predictable session identifiers in BLUEFEET Starch 0.01 through 0.14 allow remote attackers to access another user's session. Starch::Manager::state_id_seed concatenates a counter, time, Perl rand output, the PID, and reference addresses before SHA-1 hashing them. Exposure requires an application to use the default generated state ID as an authentication token; successful guessing grants only the victim session's application privileges.

CVSS severity9.1
Critical
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Predictable session identifiers in BLUEFEET Starch 0.01 through 0.14 allow remote attackers to access another user's session. Starch::Manager::state_id_seed concatenates a counter, time, Perl rand output, the PID, and reference addresses before SHA-1 hashing them. Exposure requires an application to use the default generated state ID as an authentication token; successful guessing grants only the victim session's application privileges.

The record

CVE
CVE-2025-40925
Published
Sep 20, 2025
Updated
Sep 20, 2025
Vendor
BLUEFEET
Product
Starch
Classifications
CWE-338, CWE-340, CAPEC-115, T1550.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 20, 2025Record 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=0.01 <=0.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

BLUEFEET · Starchversion=0.01 <=0.14

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CWE-340Generation of Predictable Numbers or Identifiers
CAPEC-115Authentication Bypass
T1550.004Use Alternate Authentication Material: Web Session Cookie

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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