CVE-2019-12520 Details
An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI.
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Exploit prediction scoring system (EPSS) score for CVE-2019-12520
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%).
5 Probability of exploitation activity being observed over the next 30 days (89th percentile)
CVSS score for CVE-2019-12520
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.
7.5 High
Products affected by CVE-2019-12520
Squid 2.5.stable9
Squid 2.6.stable1
Squid 2.6.stable2
Squid 2.6.stable5
Squid 2.6.stable6
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.
Low
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CVE-2019-12520 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 1,285,510 74.38%
CA 148,075 8.57%
GB 76,149 4.41%
BR 62,628 3.62%
RO 50,602 2.93%
CN 18,089 1.05%
DE 13,026 0.75%
IN 12,927 0.75%
JP 11,154 0.65%
CH 8,487 0.49%

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CVE-2019-12520 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 302,174 90.58%
Telecommunications 28,804 8.63%
Utilities 1,342 0.40%
Education 602 0.18%
Media/Entertainment 168 0.05%
Government/Politics 132 0.04%
Finance 83 0.02%
Business Services 80 0.02%
Retail 63 0.02%
Consumer Goods 38 0.01%

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