There is an Assertion 'cesu8_cursor_p == cesu8_end_p' failed at /jerry-core/lit/lit-strings.c in JerryScript 3.0.0.
###### JerryScript revision

Commit: [a6ab5e9](https://github.com/jerryscript-project/jerryscript/commit/a6ab5e9abed70cdedf9f4e9c1dc379eb762ebf64)

Version: v3.0.0



###### Build platform

Ubuntu 18.04.5 LTS (Linux 4.19.128-microsoft-standard x86_64)

Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)



###### Build steps

```bash
python ./tools/build.py --clean --debug --compile-flag=-fsanitize=address --compile-flag=-m32 --compile-flag=-g --strip=off --lto=off --logging=on --line-info=on --error-message=on --system-allocator=on --stack-limit=20
```



###### Test case
<details>
<summary>poc.js</summary>
<pre><code>

```javascript
function JSEtest() {
  const v2 = String.fromCodePoint(1337);
  const v4 = v2.padEnd(1337, v2);
  const v6 = {
      b: 0,
      e: String
  }.match
  const v7 = v6[v4];
}
JSEtest();
```
</code></pre>
</details>
​	

###### Execution steps & Output

```bash
$ ./jerryscript/build/bin/jerry poc.js

ICE: Assertion 'cesu8_cursor_p == cesu8_end_p' failed at /jerryscript/jerry-core/lit/lit-strings.c(lit_convert_cesu8_string_to_utf8_string):868.
Error: ERR_FAILED_INTERNAL_ASSERTION
[1]   abort      jerry poc.js
```
Credits: Found by OWL337 team.

Assertion 'cesu8_cursor_p == cesu8_end_p' failed at /jerryscript/jerry-core/lit/lit-strings.c(lit_convert_cesu8_string_to_utf8_string):868.
This is a GitHub Issue
repo:jerryscript
owner:jerryscript-project
Title : Assertion 'cesu8_cursor_p == cesu8_end_p' failed at /jerryscript/jerry-core/lit/lit-strings.c(lit_convert_cesu8_string_to_utf8_string):868.
Issue date:

--- start body ---
###### JerryScript revision

Commit: [a6ab5e9](https://github.com/jerryscript-project/jerryscript/commit/a6ab5e9abed70cdedf9f4e9c1dc379eb762ebf64)

Version: v3.0.0



###### Build platform

Ubuntu 18.04.5 LTS (Linux 4.19.128-microsoft-standard x86_64)

Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)



###### Build steps

```bash
python ./tools/build.py --clean --debug --compile-flag=-fsanitize=address --compile-flag=-m32 --compile-flag=-g --strip=off --lto=off --logging=on --line-info=on --error-message=on --system-allocator=on --stack-limit=20
```



###### Test case
<details>
<summary>poc.js</summary>
<pre><code>

```javascript
function JSEtest() {
  const v2 = String.fromCodePoint(1337);
  const v4 = v2.padEnd(1337, v2);
  const v6 = {
      b: 0,
      e: String
  }.match
  const v7 = v6[v4];
}
JSEtest();
```
</code></pre>
</details>
​	

###### Execution steps & Output

```bash
$ ./jerryscript/build/bin/jerry poc.js

ICE: Assertion 'cesu8_cursor_p == cesu8_end_p' failed at /jerryscript/jerry-core/lit/lit-strings.c(lit_convert_cesu8_string_to_utf8_string):868.
Error: ERR_FAILED_INTERNAL_ASSERTION
[1]   abort      jerry poc.js
```
Credits: Found by OWL337 team.

--- end body ---

An assertion failure in JerryScript v3.0.0 indicates a potential vulnerability in the string handling functionality, specifically in the conversion of CESU-8 strings to UTF-8. This could lead to unexpected behavior or crashes when processing specially crafted input, which may be exploited by an attacker.