SB2020092816 - Ubuntu update for squid3
Published: September 28, 2020 Updated: April 23, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2020-15049)
The vulnerability allows a remote attacker to perform cache poisoning attack.
The vulnerability exists in the way Squid processes client's requests. A remote client can send specially crafted data in the request to perform request smuggling and poison the HTTP cache contents with crafted HTTP(S) request messages.
Successful exploitation of the vulnerability requires an upstream server to participate in the smuggling and generate the poison response sequence.
2) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2020-15810)
The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP requests. A remote authenticated attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.
3) HTTP response splitting (CVE-ID: CVE-2020-15811)
The vulnerability allows a remote attacker to perform HTTP splitting attacks.
The vulnerability exists due to software does not corrector process CRLF character sequences. A remote authenticated attacker can send specially crafted request containing CRLF sequence and make the application to send a split HTTP response.
Successful exploitation of the vulnerability may allow an attacker perform cache poisoning attack.
4) Resource exhaustion (CVE-ID: CVE-2020-24606)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly EOF in peerDigestHandleReply() function in peer_digest.cc when processing Cache Digest response messages from a trusted peer. A remote attacker who controls a trusted peer can consume all available CPU cycles and perform a denial of service (DoS) attack.
This attack is limited to Squid using cache_peer with cache digests feature.
Remediation
Install update from vendor's website.