Amazon Linux AMI update for squid

1) Out-of-bounds write

EUVDB-ID: #VU27665

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12519

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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.

Mitigation

Update the affected packages:

i686:
    squid-3.5.20-15.39.amzn1.i686
    squid-debuginfo-3.5.20-15.39.amzn1.i686
    squid-migration-script-3.5.20-15.39.amzn1.i686

src:
    squid-3.5.20-15.39.amzn1.src

x86_64:
    squid-migration-script-3.5.20-15.39.amzn1.x86_64
    squid-3.5.20-15.39.amzn1.x86_64
    squid-debuginfo-3.5.20-15.39.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1378.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Out-of-bounds write

EUVDB-ID: #VU27667

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12521

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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.

Mitigation

Update the affected packages:

i686:
    squid-3.5.20-15.39.amzn1.i686
    squid-debuginfo-3.5.20-15.39.amzn1.i686
    squid-migration-script-3.5.20-15.39.amzn1.i686

src:
    squid-3.5.20-15.39.amzn1.src

x86_64:
    squid-migration-script-3.5.20-15.39.amzn1.x86_64
    squid-3.5.20-15.39.amzn1.x86_64
    squid-debuginfo-3.5.20-15.39.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1378.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Buffer overflow

EUVDB-ID: #VU20445

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12525

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input passed via the Proxy-Authorization header when Squid is configured to use HTTP Digest authentication . A remote attacker can send specially crafted HTTP request to the proxy server and perform denial of service attack.

Mitigation

Update the affected packages:

i686:
    squid-3.5.20-15.39.amzn1.i686
    squid-debuginfo-3.5.20-15.39.amzn1.i686
    squid-migration-script-3.5.20-15.39.amzn1.i686

src:
    squid-3.5.20-15.39.amzn1.src

x86_64:
    squid-migration-script-3.5.20-15.39.amzn1.x86_64
    squid-3.5.20-15.39.amzn1.x86_64
    squid-debuginfo-3.5.20-15.39.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1378.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Integer overflow

EUVDB-ID: #VU27666

Risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-11945

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

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.

Mitigation

Update the affected packages:

i686:
    squid-3.5.20-15.39.amzn1.i686
    squid-debuginfo-3.5.20-15.39.amzn1.i686
    squid-migration-script-3.5.20-15.39.amzn1.i686

src:
    squid-3.5.20-15.39.amzn1.src

x86_64:
    squid-migration-script-3.5.20-15.39.amzn1.x86_64
    squid-3.5.20-15.39.amzn1.x86_64
    squid-debuginfo-3.5.20-15.39.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2020-1378.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.