In the Linux kernel, the following vulnerability has been resolved:
sctp: validate embedded address parameter length
sctp_verify_asconf() and sctp_verify_param() only validate ADD_IP, DEL_IP,
and SET_PRIMARY parameters against a fixed minimum size of sizeof(struct
sctp_addip_param) + sizeof(struct sctp_paramhdr). This ensures the outer
parameter is large enough to contain an embedded address parameter header,
but does not verify that the embedded address parameter's declared length
fits within the bounds of the outer parameter.
Later, sctp_process_param() and sctp_process_asconf_param() extract the
embedded address parameter and pass it to af->from_addr_param(), which uses
the address parameter length to parse the variable-length address payload.
A malformed peer can therefore advertise an embedded address parameter
length that exceeds the remaining bytes in the enclosing parameter.
Validate that addr_param->p.length does not exceed the space available
after the sctp_addip_param header before processing the embedded address
parameter. Reject malformed parameters when the embedded address length
extends beyond the enclosing parameter bounds.
This prevents out-of-bounds reads when parsing malformed parameters carried
in INIT or ASCONF processing paths.
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS Score: 9.1
AV:N - The bug is reached when the kernel parses SCTP INIT/INIT-ACK or ASCONF chunks from a remote peer via sctp_rcv() -> sctp_do_sm() -> sctp_process_init()/sctp_process_asconf(), so any routable attacker can deliver the malformed ADD-IP/SET_PRIMARY TLVs over the network.
AC:L - Exploitation is deterministic packet crafting (minimal outer TLV length with an oversized embedded address length); no race, memory-layout lottery, or victim-specific state is required beyond a target that has SCTP ADD-IP/asconf enabled, which is a normal configuration for SCTP HA/telecom servers.
PR:N - No local privileges or pre-existing credentials are needed; an unauthenticated remote peer can send a crafted INIT to a listening SCTP endpoint or complete a handshake and send ASCONF/INIT-ACK traffic, and the vulnerable parsing runs before any application-level authentication.
UI:N - Exploitation requires only sending SCTP packets to a reachable endpoint; no victim must open files, click links, or perform any interactive action beyond ordinary network exposure of an SCTP service.
S:U - Impact is confined to the kernel SCTP stack on the receiving host (out-of-bounds kernel reads and possible crash); it does not cross a VM, container, or IOMMU security boundary.
C:H - from_addr_param() performs out-of-bounds reads of up to 16 bytes (IPv6 address field) beyond the enclosing parameter boundary when the embedded length is inflated, exposing adjacent skb/kernel memory per kernel CVSS guidance that out-of-bounds reads warrant High confidentiality impact.
I:N - The defect is an out-of-bounds read only; no kernel memory is written and the fix does not address any write primitive, so integrity impact is None.
A:H - Reading beyond the validated parameter bounds can access unmapped memory past the skb chunk and trigger a kernel fault/oops on affected builds; even when bounded within the skb, this class of SCTP parser OOB reads is treated as High availability impact because it is remotely triggerable and may panic the host.
| Attack Vector |
Network |
Scope |
Unchanged |
| Attack Complexity |
Low |
Confidentiality Impact |
High |
| Privileges Required |
None |
Integrity Impact |
None |
| User Interaction |
None |
Availability Impact |
High |
AV:N - The bug is reached when the kernel parses SCTP INIT/INIT-ACK or ASCONF chunks from a remote peer via sctp_rcv() -> sctp_do_sm() -> sctp_process_init()/sctp_process_asconf(), so any routable attacker can deliver the malformed ADD-IP/SET_PRIMARY TLVs over the network.
AC:L - Exploitation is deterministic packet crafting (minimal outer TLV length with an oversized embedded address length); no race, memory-layout lottery, or victim-specific state is required beyond a target that has SCTP ADD-IP/asconf enabled, which is a normal configuration for SCTP HA/telecom servers.
PR:N - No local privileges or pre-existing credentials are needed; an unauthenticated remote peer can send a crafted INIT to a listening SCTP endpoint or complete a handshake and send ASCONF/INIT-ACK traffic, and the vulnerable parsing runs before any application-level authentication.
UI:N - Exploitation requires only sending SCTP packets to a reachable endpoint; no victim must open files, click links, or perform any interactive action beyond ordinary network exposure of an SCTP service.
S:U - Impact is confined to the kernel SCTP stack on the receiving host (out-of-bounds kernel reads and possible crash); it does not cross a VM, container, or IOMMU security boundary.
C:H - from_addr_param() performs out-of-bounds reads of up to 16 bytes (IPv6 address field) beyond the enclosing parameter boundary when the embedded length is inflated, exposing adjacent skb/kernel memory per kernel CVSS guidance that out-of-bounds reads warrant High confidentiality impact.
I:N - The defect is an out-of-bounds read only; no kernel memory is written and the fix does not address any write primitive, so integrity impact is None.
A:H - Reading beyond the validated parameter bounds can access unmapped memory past the skb chunk and trigger a kernel fault/oops on affected builds; even when bounded within the skb, this class of SCTP parser OOB reads is treated as High availability impact because it is remotely triggerable and may panic the host.
CVSS 3.1