CVE-2024-52811 — HIGH (8.2)

Vulnerability Description

The ngtcp2 project is an effort to implement IETF QUIC protocol in C. In affected versions acks are not validated before being written to the qlog leading to a buffer overflow. In `ngtcp2_conn::conn_recv_pkt` for an ACK, there was new logic that got added to skip `conn_recv_ack` if an ack has already been processed in the payload. However, this causes us to also skip `ngtcp2_pkt_validate_ack`. The ack which was skipped still got written to qlog. The bug occurs in `ngtcp2_qlog::write_ack_frame`. It is now possible to reach this code with an invalid ack, suppose `largest_ack=0` and `first_ack_range=15`. Subtracting `largest_ack - first_ack_range` will lead to an integer underflow which is 20 chars long. However, the ngtcp2 qlog code assumes the number written is a signed integer and only accounts for 19 characters of overhead (see `NGTCP2_QLOG_ACK_FRAME_RANGE_OVERHEAD`). Therefore, we overwrite the buffer causing a heap overflow. This is high priority and could potentially impact many users if they enable qlog. qlog is disabled by default. Due to its overhead, it is most likely used for debugging purpose, but the actual use is unknown. ngtcp2 v1.9.1 fixes the bug and users are advised to upgrade. Users unable to upgrade should not turn on qlog.

CVSS Score

8.2

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

HIGH

Related Weaknesses (CWE)

CWE-670

References

FAQ

What is CVE-2024-52811?

CVE-2024-52811 is a vulnerability with a CVSS score of 8.2 (HIGH). The ngtcp2 project is an effort to implement IETF QUIC protocol in C. In affected versions acks are not validated before being written to the qlog leading to a buffer overflow. In `ngtcp2_conn::conn_r...

How severe is CVE-2024-52811?

CVE-2024-52811 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2024-52811?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.