VulnerabilityModified

CVE-2019-17638

If the Jetty version cannot be upgraded, the vulnerability can be significantly reduced by configuring a responseHeaderSize significantly larger than the requestHeaderSize (12KB responseHeaderSize and 8KB requestHeaderSize).

CRITICAL 9.4EPSS 11.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 11.1%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

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 other data. Thread1 then proceeds to write the buffer that now contains different data. This results in client1, which issued request1 seeing data from another request or response which could contain sensitive data belonging to client2 (HTTP session ids, authentication credentials, etc.). If the Jetty version cannot be upgraded, the vulnerability can be significantly reduced by configuring a responseHeaderSize significantly larger than the requestHeaderSize (12KB responseHeaderSize and 8KB requestHeaderSize).

CVSS 3.1: 9.4 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS: 11.14% probability · 96th percentile
CISA KEV: Not listed
Weakness: CWE-672, CWE-675
Affected: eclipse/jetty
Source: emo@eclipse.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.