Vulnerabilities > CVE-2018-20796 - Uncontrolled Recursion vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by '(\227|)(\\1\\1|t1|\\\2537)+' in grep.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- XML Nested Payloads Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By nesting XML data and causing this data to be continuously self-referential, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization. An attacker's goal is to leverage parser failure to his or her advantage. In most cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it may be possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.230.1].
- XML Oversized Payloads Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By supplying oversized payloads in input vectors that will be processed by the XML parser, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization, and potentially cause execution of arbitrary code. An attacker's goal is to leverage parser failure to his or her advantage. In many cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it is possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.231.1].
- Violating Implicit Assumptions Regarding XML Content (aka XML Denial of Service (XDoS)) XML Denial of Service (XDoS) can be applied to any technology that utilizes XML data. This is, of course, most distributed systems technology including Java, .Net, databases, and so on. XDoS is most closely associated with web services, SOAP, and Rest, because remote service requesters can post malicious XML payloads to the service provider designed to exhaust the service provider's memory, CPU, and/or disk space. The main weakness in XDoS is that the service provider generally must inspect, parse, and validate the XML messages to determine routing, workflow, security considerations, and so on. It is exactly these inspection, parsing, and validation routines that XDoS targets. There are three primary attack vectors that XDoS can navigate Target CPU through recursion: attacker creates a recursive payload and sends to service provider Target memory through jumbo payloads: service provider uses DOM to parse XML. DOM creates in memory representation of XML document, but when document is very large (for example, north of 1 Gb) service provider host may exhaust memory trying to build memory objects. XML Ping of death: attack service provider with numerous small files that clog the system. All of the above attacks exploit the loosely coupled nature of web services, where the service provider has little to no control over the service requester and any messages the service requester sends.
- XML Parser Attack Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. These adverse effects may include the parser crashing, consuming too much of a resource, executing too slowly, executing code supplied by an attacker, allowing usage of unintended system functionality, etc. An attacker's goal is to leverage parser failure to his or her advantage. In some cases it may be possible to jump from the data plane to the control plane via bad data being passed to an XML parser. [R.99.1]
Nessus
NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1478.NASL description According to the versions of the glibc packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities : - In the GNU C Library (aka glibc or libc6) through 2.28, the getaddrinfo function would successfully parse a string that contained an IPv4 address followed by whitespace and arbitrary characters, which could lead applications to incorrectly assume that it had parsed a valid string, without the possibility of embedded HTTP headers or other potentially dangerous substrings.(CVE-2016-10739) - Stack-based buffer overflow in the glob implementation in GNU C Library (aka glibc) before 2.24, when GLOB_ALTDIRFUNC is used, allows context-dependent attackers to cause a denial of service (crash) via a long name.(CVE-2016-1234) - Use-after-free vulnerability in the clntudp_call function in sunrpc/clnt_udp.c in the GNU C Library (aka glibc or libc6) before 2.26 allows remote attackers to have unspecified impact via vectors related to error path.(CVE-2017-12133) - In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-04-30 modified 2020-04-16 plugin id 135640 published 2020-04-16 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135640 title EulerOS Virtualization 3.0.2.2 : glibc (EulerOS-SA-2020-1478) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1152.NASL description According to the versions of the glibc packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - GNU Libc current is affected by: Re-mapping current loaded libray with malicious ELF file. The impact is: In worst case attacker may evaluate privileges. The component is: libld. The attack vector is: Attacker sends 2 ELF files to victim and asks to run ldd on it. ldd execute code.(CVE-2019-1010023) - ** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-05-03 modified 2020-02-25 plugin id 133986 published 2020-02-25 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/133986 title EulerOS 2.0 SP8 : glibc (EulerOS-SA-2020-1152) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1514.NASL description According to the versions of the glibc packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities : - The string component in the GNU C Library (aka glibc or libc6) through 2.28, when running on the x32 architecture, incorrectly attempts to use a 64-bit register for size_t in assembly codes, which can lead to a segmentation fault or possibly unspecified other impact, as demonstrated by a crash in __memmove_avx_unaligned_erms in sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S during a memcpy.(CVE-2019-6488) - ** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-05-08 modified 2020-05-01 plugin id 136217 published 2020-05-01 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/136217 title EulerOS Virtualization for ARM 64 3.0.2.0 : glibc (EulerOS-SA-2020-1514) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1102.NASL description According to the versions of the glibc packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - ** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-05-06 modified 2020-02-24 plugin id 133903 published 2020-02-24 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/133903 title EulerOS 2.0 SP5 : glibc (EulerOS-SA-2020-1102) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1330.NASL description According to the versions of the glibc packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities : - ** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-04-07 modified 2020-04-02 plugin id 135117 published 2020-04-02 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135117 title EulerOS Virtualization for ARM 64 3.0.6.0 : glibc (EulerOS-SA-2020-1330) NASL family Huawei Local Security Checks NASL id EULEROS_SA-2020-1388.NASL description According to the versions of the glibc packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by last seen 2020-05-06 modified 2020-04-15 plugin id 135517 published 2020-04-15 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/135517 title EulerOS 2.0 SP3 : glibc (EulerOS-SA-2020-1388)
References
- https://lists.gnu.org/archive/html/bug-gnulib/2019-01/msg00108.html
- https://debbugs.gnu.org/cgi/bugreport.cgi?bug=34141
- http://www.securityfocus.com/bid/107160
- https://security.netapp.com/advisory/ntap-20190315-0002/
- https://support.f5.com/csp/article/K26346590?utm_source=f5support&%3Butm_medium=RSS