Vulnerability identifier: #VU34161

Vulnerability risk: High

CVSSv3.1: 8.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-17638

CWE-ID: CWE-672

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Jetty
Server applications / Web servers

Vendor: Eclipse

Description

The vulnerability allows a remote non-authenticated attacker to #BASIC_IMPACT#.

In Eclipse Jetty, versions 9.4.27.v20200227 to 9.4.29.v20200521, in case of too large response headers, Jetty throws an exception to produce an HTTP 431 error. When this happens, the ByteBuffer containing the HTTP response headers is released back to the ByteBufferPool twice. Because of this double release, two threads can acquire the same ByteBuffer from the pool and while thread1 is about to use the ByteBuffer to write response1 data, thread2 fills the ByteBuffer with response2 data. Thread1 then proceeds to write the buffer that now contains response2 data. This results in client1, which issued request1 and expects responses, to see response2 which could contain sensitive data belonging to client2 (HTTP session ids, authentication credentials, etc.).

Mitigation
Install update from vendor's website.

Vulnerable software versions

Jetty: 9.4.27 - 9.4.29

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External links
http://bugs.eclipse.org/bugs/show_bug.cgi?id=564984

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.