SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-61910

A BPv7 bundle with a malformed extension block causes uncontrolled memory allocation inside ION-DTN 4.1.3s, leading to receiver thread termination and a Denial-of-Service (DoS).

HIGH 7.5EPSS 0.36%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The NASA’s Interplanetary Overlay Network (ION) is an implementation of Delay/Disruption Tolerant Networking (DTN). A BPv7 bundle with a malformed extension block causes uncontrolled memory allocation inside ION-DTN 4.1.3s, leading to receiver thread termination and a Denial-of-Service (DoS). The triggering bundle contains an extension block starting at `0x85070201005bbb0e20b4ea001a000927c0...`. The first byte in the extension block (0x85) indicates a CBOR array of five elements of which the first four are numbers (0x07, 0x02, 0x01, 0x00) but the fifth element is a byte string of length 27 (`0x5bbb0e20b4ea001a000927c0...`). The vulnerability seems to be due to processing the fifth element of the array (i.e., the byte string) as replacing it with a number makes the vulnerability no longer be triggered. While parsing this extension block, ION obtains a very large block length, which in the code in `bei.c`:764) seems to be passed from `blockLength` which is an unsigned int, to a 32 bit signed integer `blkSize`. The unsigned to signed conversion causes `blkSize` to hold the value of -369092043, which is then converted into a 64-bit unsigned value inside `MTAKE(blkSize)`, resulting in an attempt to allocate an unrealistic amount of memory, causing the error. As of time of publication, no known patched versions of BPv7 exist.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.36% probability · 29th percentile
CISA KEV
Not listed
Weakness
CWE-789
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.