Bug 2282568 (CVE-2021-47245)

Summary:	CVE-2021-47245 kernel: netfilter: synproxy: Fix out of bounds when parsing TCP options
Product:	[Other] Security Response	Reporter:	ybuenos
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, aquini, bhu, chwhite, cye, cyin, dbohanno, debarbos, dfreiber, drow, dvlasenk, esandeen, ezulian, hkrzesin, jarod, jbenc, jburrell, jdenham, jfaracco, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, ldoskova, lgoncalv, lzampier, mbenatto, mleitner, mmilgram, mstowell, nmurray, psutter, ptalbert, rparrazo, rrobaina, rvrbovsk, rysulliv, scweaver, sidakwo, sukulkar, tglozar, tyberry, vkumar, wcosta, williams, wmealing, ycote, ykopkova, zhijwang
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 4.4.274, kernel 4.9.274, kernel 4.14.238, kernel 4.19.196, kernel 5.4.128, kernel 5.10.46, kernel 5.12.13, kernel 5.13	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the Linux kernel's netfilter system, in the synproxy TCP option parser. This issue allows the parser to read one byte beyond its intended limit when processing TCP options, which could lead to unexpected behavior or crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2282975

Description ybuenos 2024-05-22 15:02:02 UTC

In the Linux kernel, the following vulnerability has been resolved:

netfilter: synproxy: Fix out of bounds when parsing TCP options

The Linux kernel CVE team has assigned CVE-2021-47245 to this issue.

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024052143-CVE-2021-47245-13d9@gregkh/T

Comment 3 Phil Sutter 2024-05-23 22:38:52 UTC

The fix is upstream since v5.13, so RHEL9/C9S is entirely unaffected. I'll therefore close RHEL-38056. Feel free to reopen in case you need it for documentation purposes or something.

Comment 6 Alex 2024-06-09 16:09:27 UTC

The result of automatic check (that is developed by Alexander Larkin) for this CVE-2021-47245 is: CHECK	Maybe valid. Check manually. with impact MODERATE (that is an approximation based on flags REMOTE WRITE OOB SIMPLEFIX NETFILTER  ; these flags parsed automatically based on patch data). Such automatic check happens only for Low/Moderates (and only when not from reporter, but parsing already existing CVE). Highs always checked manually (I check it myself and then we check it again in Remediation team). In rare cases some of the Moderates could be increased to High later.