Description
Multiple integer overflows in pktlength.c in Chrony before 1.29 allow remote attackers to cause a denial of service (crash) via a crafted (1) REQ_SUBNETS_ACCESSED or (2) REQ_CLIENT_ACCESSES command request to the PKL_CommandLength function or crafted (3) RPY_SUBNETS_ACCESSED, (4) RPY_CLIENT_ACCESSES, (5) RPY_CLIENT_ACCESSES_BY_INDEX, or (6) RPY_MANUAL_LIST command reply to the PKL_ReplyLength function, which triggers an out-of-bounds read or buffer overflow. NOTE: versions 1.27 and 1.28 do not require authentication to exploit.
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 | chrony | 1.29-1 | — |
| Debian 13 | chrony | 1.29-1 | — |
| Debian 12 | chrony | 1.29-1 | — |
| Debian 7 | chrony | 1.24-3.1+deb7u2 | DSA-2760-1 |
| Debian 6.0 | chrony | 1.24-3+squeeze1 | DSA-2760-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | chrony | 2.4.1-1.1 | openSUSE-SU-2024:10345-1 |
Advisories 2
- DSA-2760-1 chrony - several Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10345-1 chrony-2.4.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- [chrony-announce] 20130808 chrony-1.29 released (security) mailing-list
- DSA-2760 vendor-advisory
- [oss-security] 20130809 [Not a CVE request, just notification] CVE-2012-4502, CVE-2012-4503 -- Two security flaws fixed in Chrony v1.29 mailing-list
- http://git.tuxfamily.org/chrony/chrony.git/?p=chrony/chrony.git%3Ba=commitdiff%3Bh=7712455d9aa33d0db0945effaa07e900b85987b1
- https://bugzilla.redhat.com/show_bug.cgi?id=846392