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Technical information leak - Console functions


The application uses console functions: log, info, warning. The usage of these functions in productions environments may lead to information leakages and reveal vulnerable methods, technologies, or logic.


Gather technical information to craft more complex attack vectors.


Avoid the use of console functions in production environments. Instead, encourage the use of logs to register errors and exceptional events


Authenticated attacker from the Internet.

Expected Remediation Time

⌚ 15 minutes.


Default score using CVSS 3.1. It may change depending on the context of the src.


  • Attack vector: N
  • Attack complexity: H
  • Privileges required: L
  • User interaction: N
  • Scope: U
  • Confidentiality: L
  • Integrity: N
  • Availability: N


  • Exploit code madurity: P
  • Remediation level: O
  • Report confidence: X


  • Vector string: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:X
  • Score:
    • Base: 3.1
    • Temporal: 2.8
  • Severity:
    • Base: Low
    • Temporal: Low

Score 4.0

Default score using CVSS 4.0 . It may change depending on the context of the src.

Base 4.0

  • Attack vector: N
  • Attack complexity: H
  • Attack Requirements: N
  • Privileges required: L
  • User interaction: N
  • Confidentiality (VC): L
  • Integrity (VI): N
  • Availability (VA): N
  • Confidentiality (SC): N
  • Integrity (SI): N
  • Availability (SA): N

Threat 4.0

  • Exploit madurity: P

Result 4.0

  • Vector string: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
  • Score:
    • CVSS-BT: 1.3
  • Severity:
    • CVSS-BT: Low


In front-end programming, JavaScript's Console object provides access to the browser's debugging console[^1]. Arguments passed to log, warn and error methods are visible to the user that is using the website, it's also visible to attackers.

As per Fluid Attacks' criteria[^2] the application must not disclose internal system information such as stack traces because this information can be leveraged to further exploit other vulnerabilities.

Developers tend to do debugging the following way:

try { /* Business logic code goes here ... */ }
catch (err) {

But this ends in lots of information that attackers use to better understand the inner workings on the system, aiding them in creating and improving attack vectors.

Error: <rect> attribute x: Expected length, "NaN".
(anonymous) @
Error: <rect> attribute y: Expected length, "NaN".
(anonymous) @
Error: <rect> attribute transform: Expected number, "rotate(NaN, NaN, NaN)".



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