GHSA-3q5p-3558-364f Fiber unauthorized access vulnerability in `ctx.IsFromLocal()`

• Go github.com/gofiber/fiber: <= 1.14.6 (no fix yet) • Go github.com/gofiber/fiber/v2: < 2.49.2 → fixed in 2.49.2

Impact This vulnerability can be categorized as a security misconfiguration. It impacts users of our project who rely on the ctx.IsFromLocal() method to restrict access to localhost requests. If exploited, it could allow unauthorized access to resources intended only for localhost. In it's implementation it uses c.IPs(): ```go // IPs returns a string slice of IP addresses specified in the X-Forwarded-For request header. // When IP validation is enabled, only valid IPs are returned. func (c *Ctx) IPs() []string { return c.extractIPsFromHeader(HeaderXForwardedFor) } ``` Thereby, setting `X-Forwarded-For: 127.0.0.1` in a request from a foreign host, will result in true for ctx.IsFromLocal() Patches This issue has been patched in `v2.49.2` with commit b8c9ede6efa231116c4bd8bb9d5e03eac1cb76dc Workarounds Currently, there are no known workarounds to remediate this vulnerability without upgrading to the patched version. We strongly advise users to apply the patch as soon as it is released. References For further information and context regarding this security issue, please refer to the following resources: • Mozilla Developer Network - X-Forwarded-For