QID 355348

Date Published: 2023-06-07

QID 355348: Amazon Linux Security Advisory for squid : ALAS-2023-1757

An issue was discovered in squid before 4.9.
When handling a urn request, a corresponding http request is made.
This http request doesn't go through the access checks that incoming http requests go through.
This causes all access checks to be bypassed and allows access to restricted http servers, e.g., an attacker can connect to http servers that only listen on localhost. (
( CVE-2019-12523) an issue was discovered in squid 3.x and 4.x through 4.8.
Due to incorrect input validation, there is a heap-based buffer overflow that can result in denial of service to all clients using the proxy.
Severity is high due to this vulnerability occurring before normal security checks; any remote client that can reach the proxy port can trivially perform the attack via a crafted uri scheme. (
( CVE-2019-18676)



Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

Successful exploitation of this vulnerability could lead to a securitybreach or could affect integrity, availability, and confidentiality.

  • CVSS V3 rated as Critical - 9.1 severity.
  • CVSS V2 rated as High - 6.4 severity.
    • Solution
    Please refer to Amazon advisory: ALAS-2023-1757 for affected packages and patching details, or update with your package manager.
    Vendor References

    CVEs related to QID 355348

    CVE-2019-18676 | CVE-2019-12523 |
    Software Advisories
    Advisory ID Software Component Link
    ALAS-2023-1757 amazon linux URL Logo alas.aws.amazon.com/ALAS-2023-1757.html
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