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CISA Releases a Directive Asking Organizations to Patch Known Exploited Vulnerabilities

Posted on Nov 22, 2021 | Updated on August 8, 2022 | By Surojoy Gupta, Priya Ravindran, Pavithra Shankar

DHS CISA released a Binding Directive mandating organizations to patch a list of Known Exploited Vulnerabilities on November 03, 2021, with specified deadlines. This catalog started with 287 vulnerabilities, and the count stands at 790 today. This blog performs risk-based scrutiny of the vulnerabilities and urges organizations to reduce their risk by remediating oft-exploited vulnerabilities. 

 

Our researchers deep-dived into these vulnerabilities to understand the criticality of these CVEs and why they need to be addressed within the deadlines specified by CISA.

Firstly, let us look at how many vulnerabilities ought to be patched immediately.

CVEs to be patched by August 2022

We have already crossed the patching deadline for 755 of the CISA KEVs. There are a further 27 vulnerabilities that need to be patched by the end of August 2022. Let's take a deep dive into these vulnerabilities:

 

We also deep-dived into the CISA KEVs and here are the highlights from our analysis.

Threat Analysis

A major part of our vulnerability research is the analysis of threat groups including Advanced Persistent (APT) Groups and ransomware groups that are exploiting the vulnerabilities. In this section, we discuss the threat groups associated with the Known Exploited vulnerabilities warned about by CISA.

Overall, 273 vulnerabilities have either a ransomware or an APT association. 92 of them have both ransomware and APT associations, making them highly dangerous and important to prioritize for patching. 

APTs

187 of CISA KEVs have APT associations, with over 50% of the CVEs linked to multiple groups. A huge majority of these APT groups have links to China, followed by Russian state-sponsored groups.

CVE-2012-0158 and CVE-2017-11882 have over 20 APT groups associated with each of them, making them huge favorites of threat actors.  

  • CVE-2012-0158 is a remote code execution vulnerability in Microsoft’s Windows Common Controls (MSCOMCTL.OCX). With a critical CVSS severity of 9.3, the vulnerability belongs to the weakness CWE-94, leading to code injection issues.

  • CVE-2017-11882 is a remote code execution vulnerability that exists in Microsoft Office versions 2007 to 2016.  Its weakness CWE-119, leads to Improper Restriction of Operations within the Bounds of a Memory Buffer, one of the Top 20 Most Dangerous Software Weaknesses as listed by MITRE

APT29 or the Nobelium group is the single most prolific APT amongst this group, with links to most of the APT vulnerabilities. This is the threat behind the Solarwinds supply chain attack back in December 2021.

Ransomware

178 of CISA KEVs have ransomware associations, with over 50% linked to multiple groups. Eight vulnerabilities have been identified as exploited by more than 10 ransomware groups each.

CVE-2013-7331 and CVE-2013-3896 have more than 35 groups associated with each of them, including the infamous Sodinokibi and Cerber families.

A notable call out is CVE-2017-0143 which has 11 ransomware associations and 9 APT associations, marking it as a formidable threat to organizations using Microsoft Server Message Block servers. The Citrix vulnerability, CVE-2019-19781, is another worthy mention with 12 ransomware and 7 APT associations.

Read more about the vulnerabilities called out by CISA that are associated with ransomware here.

 

Trending Threats yet to be covered by CISA KEVs

Our analysts highlight trending vulnerabilities that are yet to be added to CISA KEVs, which have the potential to cause severe impact if exploited. CSW has also repeatedly called these out in blogs and reports.

CVE

Patch

Threat Type

CVSS Severity

CVE-2022-26352

Patch Now

Ransomware

CRITICAL

CVE-2022-2294

Patch Now

Spyware

HIGH

CVE-2022-2004

Patch Now

Malware

NA

CVE-2022-2003

Patch Now

Malware

NA

CVE-2021-45461

Patch Now

Malware

CRITICAL

CVE-2020–9934

Patch Now

Spyware

MEDIUM

CVE-2019-9489

Patch Now

APT

HIGH

 

Further, there are trending threats that are not congruent with CISA KEV criteria yet, owing to factors like missing patches or evidence of active exploitation. However, our experts recommend that these threats are prioritized for patching.

CVE

Patch

Threat Type

CVSS Severity

CVE-2021-24284

NA

-

CRITICAL

CVE-2020-26879

NA

Malware

CRITICAL

CVE-2020-26878

NA

Malware

HIGH

CVE-2020-12501

NA

Malware

CRITICAL

CVE-2018-6055

Patch Now

APT

HIGH

 

Exploit Analysis

Of the 790 CISA KEVs, known public exploits are available for 389 of these vulnerabilities. These include exploits falling into four different categories:

  • Remote Code Execution that can allow attackers to execute custom code from anywhere

  • Privilege Escalation providing attackers with elevated privileges once they gain entry into a network

  • Denial of Service that can lead to network takeovers or complete shutdown

  • Web Application Exploit codes capable of compromising web applications.

Let's look into an exploit breakdown for the CISA vulnerabilities.

Exploit Type

No. of CVEs

RCE/PE

336

RCE

285

PE

171

DoS

52

WebApp

206


Note: Some CVEs have multiple exploits associated with them.

With over 40% of the vulnerabilities having dangerous RCE/PE exploit codes, it is of utmost importance that organizations address these vulnerabilities at the earliest. If exploited, the consequences could be grave.

Latency Analysis

As part of our exploit analysis, we studied the latencies in NVD disclosure that magnified the impact of the exploited vulnerabilities. 

Latency Metrics

Overall

Critical

High

Medium

Low

Exploit before patch

89

44

39

7

0

Same day

53

29

22

2

-

Exploit after patch

175

80

82

13

-

Further, we also compared latencies with respect to patches released for the vulnerabilities to understand the trends behind attacks waged by hackers and threat actors alike.

Latency Metrics

Overall

Critical

High

Medium

NA

Same day

167

67

86

13

1

Patch after NVD

160

75

68

17

-

Patch before NVD

430

152

220

56

2

We identified some interesting observations from our latency analysis of the CISA KEVs.

  • Attackers are going after vulnerabilities even if they have existing patches or workarounds. Interestingly, most of the exploit codes were made publicly available after a patch was released for the vulnerability. This makes a strong case for organizations to revisit their patching cadence and address the vulnerabilities with a higher probability of exploitation.

  • Vulnerabilities are often identified and patched before they are added to the NVD. Thus, while the NVD is a reliable source, organizations must look beyond to proactively remediate potential threats.

Read more about our deeper analysis into the latencies here.

Interesting Nuggets

CISA temporarily removes Windows vulnerability: On May 13, 2022, CISA removed CVE-2022-26925 from its KEV catalog as Microsoft botched its May patch update for the vulnerability that was being exploited and could result in authentication failures. On July 1, 2022, CISA re-added this security bug that resulted from Active Directory (AD) certificate authentication issues. CISA continues to urge administrators to apply the May updates to Windows client devices and non-domain controller Windows servers.

Weakness Analysis

The 790 CISA KEVs are manifestations of over 70 different weaknesses in software. Almost 70% of these common weakness enumerations (CWEs) are part of MITRE’s Top 41 CWEs, and 57% are categorized under OWASP’s Top 10 error categories. This highlights the serious implications of these vulnerabilities that are present across hundreds of products currently being used by thousands of users. 

Here is a look into the top five weaknesses paving the way for the CISA KEVs:

Weakness

Description

Number of vulnerabilities

OWASP Ranking

MITRE Ranking

CWE-20 Improper input validation 98 A3 (Sensitive Data Exposure) 4

CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

78

-

17

CWE-787

Out-of-bounds Write

71

-

1

CWE-78

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

51

A3 (Sensitive Data Exposure)

5

CWE-416

Use after free

46

-

7

All developers need to be aware of the weaknesses they are introducing during the design stage and take steps to avoid such errors at the source.

CSW Has Called Out Almost 30% of KEVs

CSW’s researchers have called out 190 of the 790 vulnerabilities in the past through detailed blogs, exhaustive coverage of patch watch news items, and comprehensive reports. 

Patch Analysis

About 47% of the CISA KEVs have direct patches available. For the rest, mitigations such as upgrades or workarounds are available. Overall, 50% of the CISA KEVs have workarounds. We strongly recommend organizations to immediately apply the workarounds in the event that they are unable to patch the vulnerabilities immediately.

Patching Deadlines

DHS CISA’s initiative of reducing risk through the Known Exploited Vulnerabilities (KEV) catalog is a remediation drive with strict timelines. Below, we look at the stipulated deadlines by which sets of vulnerabilities need to be patched. 

 Patching Deadlines 

 Number of CVEs 

December 2021

126

January 2022

3

February 2022

15

March 2022

103

April 2022

127

May 2022

218

June 2022

128

July 2022

35

August 2022

27

September 2022

8

 

A meticulous remediation drive is definitely the need of the hour, as it forces the hand of federal entities and critical organizations to take immediate action to improve their cyber hygiene.

 

However, with the CISA KEV list now expanding to include 700+ vulnerabilities, organizations that haven't managed to keep up are at a loss. With no threat context available, security teams are struggling to prioritize from amongst these KEVs. 

 

CSW researchers have been closely monitoring the developments, and we can help organizations understand why a certain KEV needs to be prioritized. Our definitive threat intelligence can provide the much needed threat context to connect the dots and close the gaps in your security strategy

Reach out to us for a CISA KEV assessment.

 

CSW’s security researchers have also performed the mapping of the CISA KEVs to Mitre TTPs, addressing data gaps and other challenges along the way. Read more on our research here.

 

Note: This story is continuously evolving, so please follow our blogs to keep abreast of the updates to the CISA KEV, and their detailed analysis.

 

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