SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-18678

It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently.

MEDIUM 5.3EPSS 10.9%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 10.9%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
10.93% probability · 96th percentile
CISA KEV
Not listed
Weakness
CWE-444
Affected
squid-cache/squid · canonical/ubuntu linux · debian/debian linux · fedoraproject/fedora
Source
cve@mitre.org

References

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