BugZero | F5 BugID 1849585 - A correctly encoded long Authorization param trigg...

F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

Last updated on November 5th, 2025

BugZero Risk Score
6.7 Medium

Overall: 6.7

Severity: 7.3

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: Application Security Manager

Description

Symptoms

A correctly encoded base64 string that is over 8192 triggers 'illegal base64 value' violation

Impact

False positive with 'illegal base64 value'

Conditions

Authorization param is longer than 8192 chars

Workaround

Disable the violation

Fix Information

Introduced a new BD internal max_header_length. Default is 8192 that is the same value as it was. If you want to let ASM handling auth-param longer than 8192, set larger value than the auth-param with this internal.

Change history

Links

Original Vendor Announcement

Relevant Products

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Affected versions:15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.5.0, 17.5.1, 17.5.1.2

Fixed versions: 21.0.0, 17.5.1.3, 17.1.3

Relevant Products

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Fixed versions: 21.0.0, 17.5.1.3, 17.1.3

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F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

Last updated on November 5th, 2025

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

F5 - Defect ID: 1849585

A correctly encoded long Authorization param triggers 'illegal base64 value' vaiolation

Last updated on November 5th, 2025

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.7 Medium

BugZero Risk Score
6.7 Medium