SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-1000005

When accessed, the data is read out of bounds and causes either a crash or that the (too large) data gets passed to client write.

CRITICAL 9.1EPSS 4.56%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (4.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

libcurl 7.49.0 to and including 7.57.0 contains an out bounds read in code handling HTTP/2 trailers. It was reported (https://github.com/curl/curl/pull/2231) that reading an HTTP/2 trailer could mess up future trailers since the stored size was one byte less than required. The problem is that the code that creates HTTP/1-like headers from the HTTP/2 trailer data once appended a string like `:` to the target buffer, while this was recently changed to `: ` (a space was added after the colon) but the following math wasn't updated correspondingly. When accessed, the data is read out of bounds and causes either a crash or that the (too large) data gets passed to client write. This could lead to a denial-of-service situation or an information disclosure if someone has a service that echoes back or uses the trailers for something.

CVSS 3.0
9.1 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
4.56% probability · 91th percentile
CISA KEV
Not listed
Weakness
CWE-125
Affected
haxx/libcurl · debian/debian linux · canonical/ubuntu linux
Source
cve@mitre.org

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