VulnerabilityPublished 17 Jul 2025

CVE-2025-40924: HAARG Catalyst::Plugin::Session · Generation of Predictable Numbers or Identifiers

Affects HAARG Catalyst::Plugin::SessionSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

cwe-338

What to do

Affected software

Product	Affected	Fixed in
HAARG Catalyst::Plugin::Session	Affected =0.01	Fixed in–

AI-suggested

Immediate upgrade: Organizations should upgrade Catalyst::Plugin::Session to version 0.44 or later, where the session ID generation mechanism has been improved to use cryptographically secure random number generators.
Patch backporting: For environments where upgrading is not immediately feasible, backport patches that replace the built-in rand() with a cryptographically secure RNG (e.g., Perl's Crypt::Random or /dev/urandom) and increase entropy sources.
Session management review: Implement additional session security controls such as regenerating session IDs upon authentication, enforcing short session lifetimes, and binding sessions to client IP or user-agent where appropriate.
HTTP header hardening: Remove or restrict HTTP Date headers to reduce information leakage about epoch time.
Monitoring and detection: Deploy anomaly detection to identify suspicious session ID patterns or repeated session fixation attempts.
Security testing: Conduct penetration testing focused on session management to verify the effectiveness of mitigations.
User education: Inform developers about the importance of cryptographically secure random number generation in session management to prevent recurrence.

Description

Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely. The session id is generated from a (usually SHA-1) hash of a simple counter, the epoch time, the built-in rand function, the PID and the current Catalyst context. This information is of low entropy. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

Impact

For European organizations using Catalyst::Plugin::Session in their Perl-based web applications, this vulnerability poses a serious threat to session confidentiality and integrity. Exploitation could lead to session hijacking, allowing attackers to impersonate legitimate users, access sensitive data, perform unauthorized transactions, or escalate privileges within the application. This is particularly critical for sectors handling sensitive personal data (e.g., finance, healthcare, government services) where session compromise could lead to data breaches and regulatory non-compliance under GDPR. The predictability of session IDs also increases the risk of automated attacks, potentially affecting large numbers of users. Given that many European organizations rely on Perl-based legacy systems or custom web applications, the vulnerability could have widespread impact if unpatched. Furthermore, the exposure of session IDs could facilitate further attacks such as cross-site request forgery (CSRF) or privilege escalation. The lack of known exploits suggests the vulnerability is not yet widely weaponized, but the ease of exploitation due to weak randomness means attackers could develop exploits rapidly once aware of the flaw.

CWE-340Generation of Predictable Numbers or Identifiers (opens in a new tab)
Class weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product uses a scheme that generates numbers or identifiers that are more predictable than required.
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Jul 2025, 14:01 UTC

WeaknessesCWE-340

Technical details

References

Community reviews

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