جزئیات آسیب‌پذیری

Protego is a pure-Python robots.txt parser with support for modern conventions. Prior to 0.6.2, protego._urlpattern._URLPattern._prepare_pattern_for_regex translates every asterisk in an Allow or Disallow directive into a lazy regular-expression wildcard, so a directive containing many asterisks creates exponential backtracking. After protego.Protego.parse processes a crafted robots.txt file, protego.Protego.can_fetch can spend an attacker-controlled period matching a near-miss URL and deny service to the crawler. The vulnerable path is src/protego/_urlpattern.py in the _URLPattern match logic. This issue is fixed in version 0.6.2.

• https://github.com/scrapy/protego/security/advisories/GHSA-wjmf-p669-5m5p x_refsource_CONFIRM
• https://github.com/scrapy/protego/commit/785940181659bf440ba82f1da148fade5087e858 x_refsource_MISC
• https://github.com/scrapy/protego/releases/tag/0.6.2 x_refsource_MISC