CVE-2020-15811 Details
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2020-15811
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.63 Probability of exploitation activity being observed over the next 30 days (70th percentile)
CVSS score for CVE-2020-15811
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
6.5 Medium
Products affected by CVE-2020-15811
Squid 3.0.stable1
Squid 3.0.stable2
Squid 3.0.stable4
Squid 3.0.stable7
Squid 3.0.stable8
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Not available
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CVE-2020-15811 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 1,291,356 73.76%
CA 148,687 8.49%
GB 78,707 4.50%
BR 62,772 3.59%
RO 50,642 2.89%
CN 18,675 1.07%
DE 15,039 0.86%
IN 13,430 0.77%
JP 11,476 0.66%
CH 8,509 0.49%

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CVE-2020-15811 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 308,949 90.20%
Telecommunications 30,733 8.97%
Utilities 1,347 0.39%
Education 626 0.18%
Media/Entertainment 272 0.08%
Government/Politics 171 0.05%
Business Services 87 0.03%
Finance 86 0.03%
Retail 68 0.02%
Consumer Goods 38 0.01%

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