Potential off-by-one buffer overflow vulnerability in the Zephyr FS subsystem

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• zephyrproject zephyrup to 3.4.0 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (zephyr). Independent of NVD's CPE analysis and usually ahead of it.

• zephyrproject-rtos Zephyr

  • up to and including 3.4affected · git

Other highest-scoring records for the same primary product.

• CVE-2021-3625Buffer overflow in Zephyr USB DFU DNLOAD
  40Plan
• CVE-2020-10071Insufficient publish message length validation in MQTT
  40Plan
• CVE-2020-10070MQTT buffer overflow on receive buffer
  40Plan
• CVE-2020-10062Packet length decoding error in MQTT
  40Plan
• CVE-2020-10022UpdateHub Module Copies a Variable-Size Hash String Into a Fixed-Size Array
  40Plan
• CVE-2017-14199A buffer overflow has been found in the Zephyr Project's getaddrinfo() implementation in 1.9.0 and 1.10.0.
  40Plan

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1char buf[256];2memcpy(buf, pkt->data, pkt->len);

1char buf[256];2if (pkt->len > sizeof(buf)) {3  return -EINVAL;4}5memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.