ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2_qlog_parameters_set_transport_params() serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport parameters during the QUIC handshake to cause writes beyond the buffer boundary, resulting in a stack buffer overflow. This affects deployments that enable the qlog callback and process untrusted peer transport parameters. This issue has been fixed in version 1.22.1. If developers are unable to immediately upgrade, they can disable the qlog on client.
Weakness
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ngtcp2 | Tatsuhiro-t | * | 1.22.1 (excluding) |
| Red Hat Enterprise Linux 10 | RedHat | samba-0:4.23.5-109.el10_2 | * |
| Red Hat Enterprise Linux 9 | RedHat | samba-0:4.23.5-10.el9_8 | * |
| Red Hat Enterprise Linux 9 | RedHat | samba-0:4.23.5-10.el9_8 | * |
| Red Hat Hardened Images | RedHat | ngtcp2-main-1.22.1-1.hum1 | * |
| Ngtcp2 | Ubuntu | devel | * |
| Ngtcp2 | Ubuntu | esm-apps/jammy | * |
| Ngtcp2 | Ubuntu | esm-apps/noble | * |
| Ngtcp2 | Ubuntu | esm-apps/resolute | * |
| Ngtcp2 | Ubuntu | jammy | * |
| Ngtcp2 | Ubuntu | noble | * |
| Ngtcp2 | Ubuntu | questing | * |
| Ngtcp2 | Ubuntu | resolute | * |
Potential Mitigations
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
- D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
- Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
- Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
- For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].