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Linux-Server-Management-Too…/modules/security
cschantz 8a154753bd BUG FIX #12: Variable scope issue with ratio (SYN/ESTABLISHED ratio detection)
ISSUE:
The SYN/ESTABLISHED ratio detection calculates a ratio value inside the
skip_scoring block but uses it later in the intel_tags logic OUTSIDE the block.
When skip_scoring=1 (whitelisted IP), the ratio variable is never initialized.

ROOT CAUSE:
Similar to BUG #10 (multi_vector, geo_bonus), the ratio variable was declared
as 'local' INSIDE the skip_scoring conditional block (line 2814), but referenced
at line 3030 which is OUTSIDE the block:
  - Line 2814: local ratio=$((count * 10 / established_conns))  [INSIDE skip_scoring]
  - Line 3030: [ "${ratio:-0}" -ge 30 ] && intel_tags="..." [OUTSIDE skip_scoring]

IMPACT:
- Whitelisted IPs: BAD-RATIO tag never shown (even if suspicious ratio exists)
- For skip_scoring=1 IPs, ratio defaults to 0 via ${ratio:-0}
- Intel tags incomplete for whitelisted IPs with bad SYN/ESTABLISHED ratios
- Threat assessment missing important ratio indicator

BEHAVIOR WITH BUG:
1. When skip_scoring=0: ratio is calculated and used (works)
2. When skip_scoring=1: ratio never initialized
   - [ "${ratio:-0}" -ge 30 ] → [ "${:-0}" -ge 30 ] → always false
   - BAD-RATIO tag not added to intel_tags
   - Misleading threat summary for whitelisted IPs

FIX:
Move ratio variable declaration OUTSIDE skip_scoring block (before line 2755).
Initialize to 0 like the other variables (multi_vector, geo_bonus).
Remove duplicate declaration inside skip_scoring block.

Result: ratio is always initialized and available for intel_tags logic.

LINES CHANGED:
- Added: local ratio=0 declaration before skip_scoring block
- Removed: local ratio=... from line 2814
- Changed: local ratio= to just ratio= on line 2814

VERIFICATION:
- Syntax: ✓ Pass
- Scope: ✓ Variable available both inside and outside skip_scoring
- Logic: ✓ Consistent with other scope-dependent variables

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2026-03-06 23:51:10 -05:00
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