CVE-2024-32477
Race condition when flushing input stream leads to permission prompt bypass
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Race condition when flushing input stream leads to permission prompt bypass
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
- Record
CVE-2024-32477- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-78, CWE-362
- Updated
- 2026-11-02
EUVDEUVD-2024-30286
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
- Record
EUVD-2024-30286- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
NVD
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
- Record
CVE-2024-32477- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-78, CWE-362
- Updated
- 2026-11-02
OSV
Race condition when flushing input stream leads to permission prompt bypass
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
- Record
CVE-2024-32477- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-362, CWE-78
- Updated
- 2026-11-02
OSVJLSEC-2026-106
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between libc::tcflush(0, libc::TCIFLUSH) and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the \033[6n sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.
- Record
JLSEC-2026-106- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
Deno_jllJulia |
before 2.0.0+0 | 2.0.0+0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| published | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-32477 is a high vulnerability (CVSS 7.7) in Deno, published April 18, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. Fixed in Deno_jll 2.0.0+0.