Bug 2176466 (CVE-2023-26483)

Summary:	CVE-2023-26483 gosaml2: Denial of service via `deflate`-compressed request
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
Target Milestone:	---
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Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	gosaml2 0.9.0	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the gosaml2 package library. This issue may allow attackers to craft a deflate-compressed request, which will consume significantly more memory during processing than the size of the original request. This may eventually lead to memory exhaustion and the process being killed.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Bug Depends On:
Bug Blocks:	2176467

Description Pedro Sampaio 2023-03-08 13:13:13 UTC

gosaml2 is a Pure Go implementation of SAML 2.0. SAML Service Providers using this library for SAML authentication support are likely susceptible to Denial of Service attacks. A bug in this library enables attackers to craft a `deflate`-compressed request which will consume significantly more memory during processing than the size of the original request. This may eventually lead to memory exhaustion and the process being killed. The maximum compression ratio achievable with `deflate` is 1032:1, so by limiting the size of bodies passed to gosaml2, limiting the rate and concurrency of calls, and ensuring that lots of memory is available to the process it _may_ be possible to help Go's garbage collector "keep up". Implementors are encouraged not to rely on this. This issue is fixed in version 0.9.0.

References:

https://github.com/russellhaering/gosaml2/commit/f9d66040241093e8702649baff50cc70d2c683c0
https://github.com/russellhaering/gosaml2/security/advisories/GHSA-6gc3-crp7-25w5
https://github.com/russellhaering/gosaml2/releases/tag/v0.9.0
https://pkg.go.dev/vuln/GO-2023-1602