7.5

CVE-2021-47397: sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb

Modified
AliasesUBUNTU-CVE-2021-47397DEBIAN-CVE-2021-47397
Published 21-05-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47397 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.78% chance of exploitation in the next 30 days, higher than 55.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.78%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 8 · Related 8
SUSE-SU-2024:1979-1SUSE-SU-2024:1983-1SUSE-SU-2024:2008-1SUSE-SU-2024:2011-1SUSE-SU-2024:2019-1SUSE-SU-2024:2184-1

Timeline

  1. 21-05-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb We should always check if skb_header_pointer's return is NULL before using it, otherwise it may cause null-ptr-deref, as syzbot reported: KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline] RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196 Call Trace: <IRQ> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.78%

Chance of exploitation in the next 30 days

Percentile

56%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.78% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu86 products
  • linux< 4.15.0-163.171 | < 5.4.0-91.102
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.15.0-1116.123 | < 5.4.0-1060.63
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < 77bc7dcf0fcc1519341a91788d7a2914fcfddf6d | ≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < 8c630a7b4f9dec63f08bd881ab77984a724a5124 | ≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < ec018021cf445abbe8e2f3e2a7f1dcc813cb8ea1 | ≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < 9c6591ae8e63f93c895ad5e2703c36c548aac997 | ≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < 8180611c238e11676612eb2a9828b1c7a3a4d77b | ≥ 3acb50c18d8d6650f10919464ade4dcdaf41d62f, < f7e745f8e94492a8ac0b0a26e25f2b19d342918f | 4.8
  • linux_kernel≥ 4.8, < 4.14.249 | ≥ 4.15, < 4.19.209 | ≥ 4.20, < 5.4.151 | ≥ 5.5, < 5.10.71 | ≥ 5.11, < 5.14.10 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3
Debian1 product
  • linux< 5.14.12-1

3 vendors · 89 products

References

10 links