SB2020051133 - OpenSUSE Linux update for squid

Description

This security bulletin contains information about 6 secuirty vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2019-12519)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when handling the tag esi:when within ESIExpression::Evaluate. A remote attacker can pass specially crafted data to the application, trigger out-of-bounds write and execute arbitrary code on the target system.

2) Out-of-bounds write (CVE-ID: CVE-2019-12521)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when processing untrusted input. 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.

3) Out-of-bounds read (CVE-ID: CVE-2019-12528)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition when translating FTP server listing into HTTP responses. A remote attacker can trick the victim into vising a specially crafted FTP server, trigger out-of-bounds read and gain access to memory contents of the heap.

4) Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-ID: CVE-2019-18860)

The vulnerability allows a remote attacker to perform cache poisoning attack.

The vulnerability exists due to improper input validation of HTML code within the hostname parameter in cachemgr.cgi. A remote attacker can send a specially crated HTTP request and poison the cache.

5) Integer overflow (CVE-ID: CVE-2020-11945)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow when processing HTTP Digest Authentication tokens, if memory pooling is disabled. A remote attacker can pass a specially crafted authentication nonce and execute arbitrary code on the server through the free'd nonce credentials.

In case memory pooling is enabled, a remote attacker can replay a sniffed Digest Authentication nonce to gain access  to resources that are otherwise forbidden.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

6) Buffer overflow (CVE-ID: CVE-2020-8517)

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to a boundary error in the NTLM authentication credentials parser in ext_lm_group_acl. A remote attacker can send a specially crafted HTTP request to the affected proxy server, trigger memory corruption and perform a denial of service attack.

Remediation

Install update from vendor's website.

References

• https://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html