'serve-expired-client-timeout' and 'response-ip' CNAME redirect could lead to a crash
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| NLnet Labs | Unbound | unaffected |
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No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Nlnetlabs | Unbound |
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Vendor Solution
This issue is fixed starting with version 1.25.2
| Source | ID | Title |
|---|---|---|
Debian DSA |
DSA-6507-1 | unbound security update |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.237% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Nlnetlabs
Nlnetlabs unbound |
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| Vendors & Products |
Nlnetlabs
Nlnetlabs unbound |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| Description | In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, when 'serve-expired: yes' is set together with a 'response-ip: <net> redirect' /'response-ip-data: <net> CNAME <target>' rule (or the RPZ 'rpz-cname-override' equivalent), a remote client who controls any delegated domain can crash the daemon. The serve-expired-client-timeout callback runs a two-pass loop to chase the respip-generated CNAME alias; on the second pass it resets 'alias_rrset' but not 'partial_rep'. Later, this inconsistency leads to a NULL pointer dereference and an eventual crash. A malicious actor can exploit the vulnerability by controlling any zone that replies with an A/AAAA record that falls inside the configured response-ip/rpz subnet. By delaying the answer when the previous record has expired, the vulnerable path of 'serve-expired-client-timeout' is taken leading to denial of service via the server crash. | |
| Title | 'serve-expired-client-timeout' and 'response-ip' CNAME redirect could lead to a crash | |
| Weaknesses | CWE-476 | |
| References |
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| Metrics |
cvssV3_1
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