Junos OS: Buffer Copy without Checking Size of Input
CVE-2023-22416 is a high-severity buffer copy without checking size of input vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 20.4R3-S5, 21.1R3-S4, 21.2R3-S2 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.7% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 20.4R3-S5 or 21.1R3-S4 or 21.2R3-S2 or 21.3R3-S1, whichever matches your release line, or a later version.
- Update Junos to 20.4 or a later version.
- Read the advisory on kb.juniper.net for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS | 20.4 up to, but not including, 20.4R3-S5; 21.1 up to, but not including, 21.1R3-S4; 21.2 up to, but not including, 21.2R3-S2; 21.3 up to, but not including, 21.3R3-S1; 21.4 up to, but not including, 21.4R3; 22.1 up to, but not including, 22.1R1-S2, 22.1R2; 22.2 up to, but not including, 22.2R1-S1, 22.2R2 | 20.4R3-S5, 21.1R3-S4, 21.2R3-S2, 21.3R3-S1, 21.4R3, 22.1R1-S2, 22.1R2 |
| Juniper Networks | Junos | before 20.4; 20.4; 21.1; 21.2; 21.3; 21.4; 22.1; 22.2 | 20.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (juniper.net).
Official description
A Buffer Overflow vulnerability in SIP ALG of Juniper Networks Junos OS allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). On all MX Series and SRX Series platform with SIP ALG enabled, when a malformed SIP packet is received, the flow processing daemon (flowd) will crash and restart. This issue affects: Juniper Networks Junos OS on MX Series and SRX Series 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S2; 21.3 versions prior to 21.3R3-S1; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R1-S2, 22.1R2; 22.2 versions prior to 22.2R1-S1, 22.2R2. This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1 on SRX Series.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Buffer Copy without Checking Size of Input
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
More Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Junos OS
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
Recent Buffer Copy without Checking Size of Input vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
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