CVE-2020-8244

Remote Memory Exposure in bl

A buffer over-read vulnerability exists in bl <4.0.3, <3.0.1, <2.2.1, and <1.2.3 which could allow an attacker to supply user input (even typed) that if it ends up in consume() argument and can become negative, the BufferList state can be corrupted, tricking it into exposing uninitialized memory via regular .slice() calls.

A read operation accesses a memory location beyond the intended buffer boundary. Typical impact: sensitive data disclosure or crash.

CVE-2020-8244 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.0.1, 4.0.3, 1.2.3, 2.2.1); upgrading removes the vulnerable code path.

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1. What is CVE-2020-8244? CVE-2020-8244 is a medium-severity out-of-bounds read vulnerability in bl (npm), affecting versions = 3.0.0. It is fixed in 3.0.1, 4.0.3, 1.2.3, 2.2.1. A read operation accesses a memory location beyond the intended buffer boundary.
2. How severe is CVE-2020-8244? CVE-2020-8244 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of bl are affected by CVE-2020-8244? bl (npm) versions = 3.0.0 is affected.
4. Is there a fix for CVE-2020-8244? Yes. CVE-2020-8244 is fixed in 3.0.1, 4.0.3, 1.2.3, 2.2.1. Upgrade to this version or later.
5. Is CVE-2020-8244 exploitable, and should I be worried? Whether CVE-2020-8244 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2020-8244 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2020-8244?
   • Upgrade bl to 3.0.1 or later
   • Upgrade bl to 4.0.3 or later
   • Upgrade bl to 1.2.3 or later
   • Upgrade bl to 2.2.1 or later

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