Bug 1565035 – CVE-2018-1000168 nghttp2: Null pointer dereference when too large ALTSVC frame is received

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Bug 1565035 - (CVE-2018-1000168) CVE-2018-1000168 nghttp2: Null pointer dereference when too large ALTSVC frame is received

Summary:	CVE-2018-1000168 nghttp2: Null pointer dereference when too large ALTSVC fram...

Status:	NEW

Aliases:	CVE-2018-1000168

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	medium Severity medium
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=moderate,public=20180412,repor...
Keywords:	Reopened, Security

Depends On:	1566991 1566989 1566990
Blocks:	1565488
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Reported:	2018-04-09 04:25 EDT by Adam Mariš
Modified:	2018-04-24 00:38 EDT (History)
CC List:	12 users (show)

See Also:
Fixed In Version:	nghttp2 1.31.1
Doc Type:	If docs needed, set a value
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2018-04-13 05:31:56 EDT
Type:	---
Regression:	---
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Documentation:	---
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Verified Versions:
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oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
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Attachments	(Terms of Use)
Upstream patch (1.99 KB, patch) 2018-04-10 02:29 EDT, Adam Mariš	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

Groups: None (edit)

Description Adam Mariš 2018-04-09 04:25:21 EDT

If ALTSVC frame is received by libnghttp2 and it is larger than it can accept, the pointer field which points to ALTSVC frame payload is left NULL.  Later libnghttp2 attempts to access another field through the pointer, and gets segmentation fault. The largest frame size libnghttp2 accept is by default 16384 bytes.

Receiving ALTSVC frame is disabled by default.  Application has to enable it explicitly by calling `nghttp2_option_set_builtin_recv_extension_type(opt, NGHTTP2_ALTSVC)`.

Transmission of ALTSVC is always enabled, and it does not cause this vulnerability. ALTSVC frame is expected to be sent by server, and received by client as defined in RFC 7838.

Affected versions: nghttp2 >= 1.10.0 and nghttp2 <= v1.31.0

Comment 1 Adam Mariš 2018-04-09 04:25:23 EDT

Acknowledgments:

Name: the Nghttp2 project

Comment 2 Adam Mariš 2018-04-10 02:29 EDT

Created attachment 1419700 [details]
Upstream patch

Comment 3 Stefan Cornelius 2018-04-12 07:30:25 EDT

Although rh-nodejs8-nodejs includes nghttp2, it is not affected: support for the ALTSVC frame was added in 9.4.0 via https://github.com/nodejs/node/commit/ce22d6f9178507c7a41b04ac4097b9ea902049e3#diff-8d67cefebb5e07f8f3cad3c90c402bb2

Comment 4 Stefan Cornelius 2018-04-13 05:31:56 EDT

Public via:
http://www.openwall.com/lists/oss-security/2018/04/12/4

Comment 5 Stefan Cornelius 2018-04-13 05:32:25 EDT

Created nghttp2 tracking bugs for this issue:

Affects: fedora-all [bug 1566990]
Affects: epel-7 [bug 1566989]

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