various: Incorrect Calculation of Buffer Size
CVE-2023-50736 is a critical-severity incorrect calculation of buffer size vulnerability in various from Lexmark, with a CVSS 3.1 base score of 9.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected various versions: various. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.77% chance of exploitation within 30 days, higher than 56% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of various you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on lexmark.com 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 |
|---|---|---|---|
| Lexmark | various | various | Not stated |
| Lexmark | cxtpc_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cstpc_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxtct_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxtpm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cxtmm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mslsg_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxlsg_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mslbd_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxlbd_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | msngm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cs310 | lw80.vyl.p249 and earlier | Not stated |
| Lexmark | mstgm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxngm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | ms315 | lw90.tl2.p205 and earlier | Not stated |
| Lexmark | ms610dn | lw90.pr2.p205 and earlier | Not stated |
| Lexmark | mxtgm_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | msngw_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mstgw_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | mxtgw_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cslbn_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cslbl_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cxlbn_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cxlbl_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
| Lexmark | cstzj_firmware | 230.041 and earlier; 230.075 through 230.078; 230.200 through 230.203 | Not stated |
Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. 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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA.
Official description
A memory corruption vulnerability has been identified in PostScript interpreter in various Lexmark devices. The vulnerability can be leveraged by an attacker to execute arbitrary code.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Calculation of Buffer Size
The product does not correctly calculate the size to be used when allocating a buffer.
How developers prevent this class of flaw
- When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts & characters to & for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input buffer.
- Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how the language handles numbers that are too large or too small for its underlying representation. Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
- Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
More Incorrect Calculation of Buffer Size vulnerabilities (CWE-131)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in various
- 9.1 Critical severity
- 9.0 Critical severity
- 9.0 Critical severity
Recent Incorrect Calculation of Buffer Size vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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