Important: squid

Issue Overview:

A flaw was found in squid. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this buffer, but it’s off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can’t affect adjacent memory blocks, and thus just leads to a crash while processing. (CVE-2019-12521)

Due to chunked decoder lenience Squid is vulnerable to Request/Response smuggling attacks when parsing HTTP/1.1 and ICAP messages. (CVE-2023-46846)

Affected Packages:

squid

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update squid to update your system.

New Packages:

aarch64:  
    squid-3.5.20-17.amzn2.7.20.aarch64  
    squid-sysvinit-3.5.20-17.amzn2.7.20.aarch64  
    squid-migration-script-3.5.20-17.amzn2.7.20.aarch64  
    squid-debuginfo-3.5.20-17.amzn2.7.20.aarch64  
  
i686:  
    squid-3.5.20-17.amzn2.7.20.i686  
    squid-sysvinit-3.5.20-17.amzn2.7.20.i686  
    squid-migration-script-3.5.20-17.amzn2.7.20.i686  
    squid-debuginfo-3.5.20-17.amzn2.7.20.i686  
  
src:  
    squid-3.5.20-17.amzn2.7.20.src  
  
x86_64:  
    squid-3.5.20-17.amzn2.7.20.x86_64  
    squid-sysvinit-3.5.20-17.amzn2.7.20.x86_64  
    squid-migration-script-3.5.20-17.amzn2.7.20.x86_64  
    squid-debuginfo-3.5.20-17.amzn2.7.20.x86_64  

Additional References

Red Hat: CVE-2019-12521, CVE-2023-46846

Mitre: CVE-2019-12521, CVE-2023-46846