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mod_proxy_balancer: use apr_isspace when scanning Cookie header - #675
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arshsmith1 wants to merge 1 commit into
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mod_proxy_balancer: use apr_isspace when scanning Cookie header#675arshsmith1 wants to merge 1 commit into
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1. get_cookie_param scans the client-supplied Cookie header and hands raw signed char bytes to isspace(). 2. a cookie byte >= 0x80 reaches isspace() as a negative int, outside the unsigned char / EOF domain ctype requires, which is undefined. Switched both calls to apr_isspace, which indexes via unsigned char like the rest of the proxy and http code.
arshsmith1
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Jul 6, 2026
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any update? |
notroj
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Jul 17, 2026
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Thanks for the PR |
notroj added a commit
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Aug 7, 2026
* modules/proxy/mod_proxy_balancer.c (find_session_route): Replace isspace() with apr_isspace() to avoid locale-dependent behavior and undefined behavior with negative char values. Submitted by: arshsmith1 <arshi bugqore.com> GitHub: closesapache#675 git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1936266 13f79535-47bb-0310-9956-ffa450edef68
notroj added a commit
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Aug 7, 2026
* modules/proxy/mod_proxy_balancer.c (find_session_route): Replace isspace() with apr_isspace() to avoid locale-dependent behavior and undefined behavior with negative char values. Submitted by: arshsmith1 <arshi bugqore.com> GitHub: closesapache#675 git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1936266 13f79535-47bb-0310-9956-ffa450edef68
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charbytes (start_cookie[-1]and*start_cookie) straight toisspace().charis signed, a cookie byte >= 0x80 reachesisspace()as a negative int, which is outside the unsigned-char / EOF domain the ctype functions are defined for, so the result is undefined.This is reachable on any balancer with a sticky session (
get_cookie_paramis called from find_session_route viabalancer->s->sticky), so the byte is fully attacker-controlled. Switched both calls toapr_isspace, which indexes throughunsigned charand is already what the surrounding proxy/http/server code uses everywhere else.