A buffer overrun exists in the NASA cFS component named CCSDS Header Size Handler, specifically within the CFE_SB_TransmitMsg function in file cfe_sb_priv.c. The flaw allows malicious manipulation of message data to overflow a buffer, corrupting adjacent memory. Depending on the context, this could destabilize the system or provide an attacker with a foothold for further exploitation, such as executing arbitrary code, if the overwritten memory controls critical execution paths.

The vulnerability affects all releases of NASA cFS up to and including version 7.0.0. No other cFS releases are known to be impacted, and no vendor-specified patch does yet exist.

The CVSS score is 5.1, indicating moderate severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalog, so the likelihood of active attacks is unclear. The attack vector is inferred to be local or internal to the vehicle’s onboard software, as exploitation would require sending crafted messages to the message bus subsystem. Until an official fix or workaround is released, the risk remains moderate but should be monitored closely.