The xdr_bytes and xdr_string functions in the GNU C Library (aka glibc or libc6) 2.25 mishandle failures of buffer deserialization, which allows remote attackers to cause a denial of service (virtual memory allocation, or memory consumption if an overcommit setting is not used) via a crafted UDP packet to port 111, a related issue to CVE-2017-8779. NOTE: [Information provided from upstream and references
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Glibc | Gnu | 2.25 (including) | 2.25 (including) |
| Eglibc | Ubuntu | precise | * |
| Glibc | Ubuntu | artful | * |
| Glibc | Ubuntu | vivid/stable-phone-overlay | * |
| Glibc | Ubuntu | vivid/ubuntu-core | * |
| Glibc | Ubuntu | yakkety | * |
| Glibc | Ubuntu | zesty | * |
Potential Mitigations
- Make fields transient to protect them from deserialization.
- An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
Related Attack Patterns
References
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00026.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00039.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00049.html
- http://www.openwall.com/lists/oss-security/2017/05/05/2
- http://www.securityfocus.com/bid/98339
- https://bugzilla.suse.com/show_bug.cgi?id=1037559#c7
- https://seclists.org/oss-sec/2017/q2/228
- https://sourceware.org/bugzilla/show_bug.cgi?id=21461
- https://sourceware.org/legacy-ml/libc-alpha/2017-05/msg00128.html
- https://sourceware.org/legacy-ml/libc-alpha/2017-05/msg00129.html
- https://sourceware.org/ml/libc-alpha/2017-05/msg00105.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00026.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00039.html
- http://lists.opensuse.org/opensuse-security-announce/2018-02/msg00049.html
- http://www.openwall.com/lists/oss-security/2017/05/05/2
- http://www.securityfocus.com/bid/98339
- https://bugzilla.suse.com/show_bug.cgi?id=1037559#c7
- https://seclists.org/oss-sec/2017/q2/228
- https://sourceware.org/bugzilla/show_bug.cgi?id=21461
- https://sourceware.org/legacy-ml/libc-alpha/2017-05/msg00128.html
- https://sourceware.org/legacy-ml/libc-alpha/2017-05/msg00129.html
- https://sourceware.org/ml/libc-alpha/2017-05/msg00105.html