Description
The compare_dn function in utils/identification.c in strongSwan 4.3.3 through 5.1.1 allows (1) remote attackers to cause a denial of service (out-of-bounds read, NULL pointer dereference, and daemon crash) or (2) remote authenticated users to impersonate arbitrary users and bypass access restrictions via a crafted ID_DER_ASN1_DN ID, related to an "insufficient length check" during identity comparison.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | strongswan | 5.1.0-3 | — |
| Debian 13 | strongswan | 5.1.0-3 | — |
| Debian 12 | strongswan | 5.1.0-3 | — |
| Debian 7 | strongswan | 4.5.2-1.5+deb7u2 | DSA-2789-1 |
| Debian 6.0 | strongswan | 4.4.1-5.4 | DSA-2789-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | strongswan | 5.3.5-1.1 | openSUSE-SU-2024:10579-1 |
Advisories 2
- DSA-2789-1 strongswan - Denial of service and authorization bypass Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10579-1 strongswan-5.3.5-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026