CVE-2026-73270: httpd mod_auth directory protection bypassed by request path casing on case-insensitive filesystems
httpd modauth directory protection bypassed by request path casing on case-insensitive filesystems
Other sources
Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a remote unauthenticated attacker to read files inside a modauth protected directory by requesting them with different casing, on deployments whose filesystem is case-insensitive.
— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 26.2.5.21-6 - Upgrade
Upgrade
debian/erlangto a version that resolves this vulnerability.Fixed in 1:29.0.6+dfsg-1Fixed in 1:29.1.1+dfsg-1 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 27.3.4.17 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 28.5.0.6 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 29.0.6
Event History
Frequently Asked Questions
Which deployments are exposed?
Only deployments using a case-insensitive filesystem are affected. Deployments on case-sensitive filesystems are unaffected because paths with mismatched casing are rejected by the filesystem.
Does exploitation require credentials or prior access?
No. A remote unauthenticated attacker can exploit the issue by requesting a file in a protected directory using casing that differs from the directory path configured for mod_auth.
Which releases contain fixes?
Fixed releases are OTP 27.3.4.17, OTP 28.5.0.6, and OTP 29.0.6. The corresponding fixed inets releases are 9.3.2.7, 9.6.2.3, and 9.7.2.
Are older OTP and inets releases affected?
OTP releases before 17.0, corresponding to inets releases before 5.10, have unknown affected status. They should not be assumed unaffected based on the available information.