Lexbor is a web browser engine library. Prior to 2.7.0, the ISO‑2022‑JP encoder in Lexbor fails to reset the temporary size variable between iterations. The statement ctx->buffer_used -= size with a stale size = 3 causes an integer underflow that wraps to SIZE_MAX.
Afterwards, memcpy is called with a negative length, leading to an out‑of‑bounds read from the stack and an out‑of‑bounds write to the heap. The source data is partially controllable via the contents of the DOM tree. This vulnerability is fixed in 2.7.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Lexbor Lexbor
cpe:2.3:a:lexbor:lexbor:*:*:*:*:*:*:*:*
|
— |
2.7.0
|